Heavy code style changes and slight refactoring

src/main/java/com/songoda/epichoppers/EpicHoppers.java

@@ -12,7 +12,6 @@ import com.songoda.core.database.SQLiteConnector;
 import com.songoda.core.gui.GuiManager;
 import com.songoda.core.hooks.EconomyManager;
 import com.songoda.core.hooks.ProtectionManager;
-import com.songoda.core.locale.Locale;
 import com.songoda.core.third_party.de.tr7zw.nbtapi.NBTItem;
 import com.songoda.core.utils.TextUtils;
 import com.songoda.epichoppers.boost.BoostManager;
@@ -58,8 +57,6 @@ import java.util.Collections;
 import java.util.List;
 
 public class EpicHoppers extends SongodaPlugin {
-
-    private static EpicHoppers INSTANCE;
     private final GuiManager guiManager = new GuiManager(this);
     private final Config levelsConfig = new Config(this, "levels.yml");
     private HopperManager hopperManager;
@@ -74,13 +71,8 @@ public class EpicHoppers extends SongodaPlugin {
     private DatabaseConnector databaseConnector;
     private DataManager dataManager;
 
-    public static EpicHoppers getInstance() {
-        return INSTANCE;
-    }
-
     @Override
     public void onPluginLoad() {
-        INSTANCE = this;
     }
 
     @Override
@@ -117,9 +109,9 @@ public class EpicHoppers extends SongodaPlugin {
                         new CommandSettings(this)
                 );
 
-        this.hopperManager = new HopperManager();
+        this.hopperManager = new HopperManager(this);
         this.playerDataManager = new PlayerDataManager();
-        this.containerManager = new ContainerManager(this);
+        this.containerManager = new ContainerManager();
         this.boostManager = new BoostManager();
 
         // Database stuff, go!
@@ -145,8 +137,7 @@ public class EpicHoppers extends SongodaPlugin {
         }
 
         this.dataManager = new DataManager(this.databaseConnector, this);
-        DataMigrationManager dataMigrationManager = new DataMigrationManager(this.databaseConnector, this.dataManager,
-                new _1_InitialMigration());
+        DataMigrationManager dataMigrationManager = new DataMigrationManager(this.databaseConnector, this.dataManager, new _1_InitialMigration(this));
         dataMigrationManager.runMigrations();
 
         this.loadLevelManager();
@@ -155,7 +146,7 @@ public class EpicHoppers extends SongodaPlugin {
         this.teleportHandler = new TeleportHandler(this);
 
         // Register Listeners
-        guiManager.init();
+        this.guiManager.init();
         PluginManager pluginManager = Bukkit.getPluginManager();
         pluginManager.registerEvents(new HopperListeners(this), this);
         pluginManager.registerEvents(new EntityListeners(), this);
@@ -200,24 +191,25 @@ public class EpicHoppers extends SongodaPlugin {
 
     @Override
     public List<Config> getExtraConfig() {
-        return Collections.singletonList(levelsConfig);
+        return Collections.singletonList(this.levelsConfig);
     }
 
     private void loadLevelManager() {
-        if (!new File(this.getDataFolder(), "levels.yml").exists())
+        if (!new File(this.getDataFolder(), "levels.yml").exists()) {
             this.saveResource("levels.yml", false);
-        levelsConfig.load();
+        }
+        this.levelsConfig.load();
 
         // Load an instance of LevelManager
-        levelManager = new LevelManager();
+        this.levelManager = new LevelManager();
         /*
          * Register Levels into LevelManager from configuration.
          */
-        levelManager.clear();
-        for (String levelName : levelsConfig.getKeys(false)) {
+        this.levelManager.clear();
+        for (String levelName : this.levelsConfig.getKeys(false)) {
             int level = Integer.parseInt(levelName.split("-")[1]);
 
-            ConfigurationSection levels = levelsConfig.getConfigurationSection(levelName);
+            ConfigurationSection levels = this.levelsConfig.getConfigurationSection(levelName);
 
             int radius = levels.getInt("Range");
             int amount = levels.getInt("Amount");
@@ -245,13 +237,13 @@ public class EpicHoppers extends SongodaPlugin {
                     modules.add(new ModuleAutoSmelter(this, levels.getInt("AutoSmelting")));
                 }
             }
-            levelManager.addLevel(level, costExperience, costEconomy, radius, amount, filter, teleport, linkAmount, modules);
+            this.levelManager.addLevel(level, costExperience, costEconomy, radius, amount, filter, teleport, linkAmount, modules);
         }
     }
 
     private void saveModules() {
-        if (levelManager != null) {
-            for (Level level : levelManager.getLevels().values()) {
+        if (this.levelManager != null) {
+            for (Level level : this.levelManager.getLevels().values()) {
                 for (Module module : level.getRegisteredModules()) {
                     module.saveDataToFile();
                 }
@@ -274,48 +266,52 @@ public class EpicHoppers extends SongodaPlugin {
         return nbtItem.getItem();
     }
 
-    @Override
-    public Locale getLocale() {
-        return locale;
-    }
-
     public TeleportHandler getTeleportHandler() {
-        return teleportHandler;
+        return this.teleportHandler;
     }
 
     public BoostManager getBoostManager() {
-        return boostManager;
+        return this.boostManager;
     }
 
     public CommandManager getCommandManager() {
-        return commandManager;
+        return this.commandManager;
     }
 
     public LevelManager getLevelManager() {
-        return levelManager;
+        return this.levelManager;
     }
 
     public HopperManager getHopperManager() {
-        return hopperManager;
+        return this.hopperManager;
     }
 
     public PlayerDataManager getPlayerDataManager() {
-        return playerDataManager;
+        return this.playerDataManager;
     }
 
     public GuiManager getGuiManager() {
-        return guiManager;
+        return this.guiManager;
     }
 
     public DataManager getDataManager() {
-        return dataManager;
+        return this.dataManager;
     }
 
     public DatabaseConnector getDatabaseConnector() {
-        return databaseConnector;
+        return this.databaseConnector;
     }
 
     public ContainerManager getContainerManager() {
-        return containerManager;
+        return this.containerManager;
+    }
+
+
+    /**
+     * @deprecated Use {@link #getPlugin(Class)} instead
+     */
+    @Deprecated
+    public static EpicHoppers getInstance() {
+        return EpicHoppers.getPlugin(EpicHoppers.class);
     }
 }

src/main/java/com/songoda/epichoppers/api/events/HopperAccessEvent.java

@@ -9,13 +9,22 @@ import org.bukkit.event.HandlerList;
  * Called when a hopper is accessed by a player.
  */
 public class HopperAccessEvent extends HopperEvent implements Cancellable {
-
     private static final HandlerList HANDLERS = new HandlerList();
 
     private boolean canceled = false;
 
-    public HopperAccessEvent(Player player, Hopper hopper) {
-        super(player, hopper);
+    public HopperAccessEvent(Player who, Hopper hopper) {
+        super(who, hopper);
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return this.canceled;
+    }
+
+    @Override
+    public void setCancelled(boolean cancel) {
+        this.canceled = cancel;
     }
 
     @Override
@@ -26,15 +35,4 @@ public class HopperAccessEvent extends HopperEvent implements Cancellable {
     public static HandlerList getHandlerList() {
         return HANDLERS;
     }
-
-    @Override
-    public boolean isCancelled() {
-        return canceled;
-    }
-
-    @Override
-    public void setCancelled(boolean canceled) {
-        this.canceled = canceled;
-    }
-
-}
+}

src/main/java/com/songoda/epichoppers/api/events/HopperBreakEvent.java

@@ -5,11 +5,10 @@ import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 
 public class HopperBreakEvent extends HopperEvent {
-
     private static final HandlerList HANDLERS = new HandlerList();
 
-    public HopperBreakEvent(Player player, Hopper hopper) {
-        super(player, hopper);
+    public HopperBreakEvent(Player who, Hopper hopper) {
+        super(who, hopper);
     }
 
     @Override
@@ -20,5 +19,4 @@ public class HopperBreakEvent extends HopperEvent {
     public static HandlerList getHandlerList() {
         return HANDLERS;
     }
-
 }

src/main/java/com/songoda/epichoppers/api/events/HopperEvent.java

@@ -9,7 +9,6 @@ import org.bukkit.event.player.PlayerEvent;
  * Represents an abstract {@link Event} given a {@link Player} and {@link Hopper} instance
  */
 public abstract class HopperEvent extends PlayerEvent {
-
     protected final Hopper hopper;
 
     public HopperEvent(Player who, Hopper hopper) {
@@ -23,7 +22,7 @@ public abstract class HopperEvent extends PlayerEvent {
      * @return the broken spawner
      */
     public Hopper getHopper() {
-        return hopper;
+        return this.hopper;
     }
 
-}
+}

src/main/java/com/songoda/epichoppers/api/events/HopperPlaceEvent.java

@@ -5,11 +5,10 @@ import org.bukkit.entity.Player;
 import org.bukkit.event.HandlerList;
 
 public class HopperPlaceEvent extends HopperEvent {
-
     private static final HandlerList HANDLERS = new HandlerList();
 
-    public HopperPlaceEvent(Player player, Hopper hopper) {
-        super(player, hopper);
+    public HopperPlaceEvent(Player who, Hopper hopper) {
+        super(who, hopper);
     }
 
     @Override
@@ -20,5 +19,4 @@ public class HopperPlaceEvent extends HopperEvent {
     public static HandlerList getHandlerList() {
         return HANDLERS;
     }
-
-}
+}

src/main/java/com/songoda/epichoppers/boost/BoostData.java

@@ -4,7 +4,6 @@ import java.util.Objects;
 import java.util.UUID;
 
 public class BoostData {
-
     private final int multiplier;
     private final long endTime;
     private final UUID player;
@@ -16,35 +15,40 @@ public class BoostData {
     }
 
     public int getMultiplier() {
-        return multiplier;
+        return this.multiplier;
     }
 
     public UUID getPlayer() {
-        return player;
+        return this.player;
     }
 
     public long getEndTime() {
-        return endTime;
+        return this.endTime;
     }
 
     @Override
     public int hashCode() {
-        int result = 31 * multiplier;
+        int result = 31 * this.multiplier;
 
-        result = 31 * result + (this.player == null ? 0 : player.hashCode());
-        result = 31 * result + (int) (endTime ^ (endTime >>> 32));
+        result = 31 * result + (this.player == null ? 0 : this.player.hashCode());
+        result = 31 * result + (int) (this.endTime ^ (this.endTime >>> 32));
 
         return result;
     }
 
     @Override
     public boolean equals(Object obj) {
-        if (this == obj) return true;
-        if (!(obj instanceof BoostData)) return false;
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof BoostData)) {
+            return false;
+        }
 
         BoostData other = (BoostData) obj;
-        return multiplier == other.multiplier && endTime == other.endTime
-                && Objects.equals(player, other.player);
+        return this.multiplier == other.multiplier &&
+                this.endTime == other.endTime &&
+                Objects.equals(this.player, other.player);
     }
 
 }

src/main/java/com/songoda/epichoppers/boost/BoostManager.java

@@ -7,7 +7,6 @@ import java.util.Set;
 import java.util.UUID;
 
 public class BoostManager {
-
     private final Set<BoostData> registeredBoosts = new HashSet<>();
 
     public void addBoostToPlayer(BoostData data) {
@@ -19,16 +18,19 @@ public class BoostManager {
     }
 
     public void addBoosts(List<BoostData> boosts) {
-        registeredBoosts.addAll(boosts);
+        this.registeredBoosts.addAll(boosts);
     }
 
     public Set<BoostData> getBoosts() {
-        return Collections.unmodifiableSet(registeredBoosts);
+        return Collections.unmodifiableSet(this.registeredBoosts);
     }
 
     public BoostData getBoost(UUID player) {
-        if (player == null) return null;
-        for (BoostData boostData : registeredBoosts) {
+        if (player == null) {
+            return null;
+        }
+
+        for (BoostData boostData : this.registeredBoosts) {
             if (boostData.getPlayer().toString().equals(player.toString())) {
                 if (System.currentTimeMillis() >= boostData.getEndTime()) {
                     removeBoostFromPlayer(boostData);

src/main/java/com/songoda/epichoppers/commands/CommandBoost.java

@@ -1,19 +1,20 @@
 package com.songoda.epichoppers.commands;
 
 import com.songoda.core.commands.AbstractCommand;
+import com.songoda.core.utils.NumberUtils;
+import com.songoda.core.utils.TimeUtils;
 import com.songoda.epichoppers.EpicHoppers;
 import com.songoda.epichoppers.boost.BoostData;
-import com.songoda.epichoppers.utils.Methods;
 import org.bukkit.Bukkit;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 public class CommandBoost extends AbstractCommand {
-
     private final EpicHoppers plugin;
 
     public CommandBoost(EpicHoppers plugin) {
@@ -24,11 +25,11 @@ public class CommandBoost extends AbstractCommand {
     @Override
     protected ReturnType runCommand(CommandSender sender, String... args) {
         if (args.length < 2) {
-            plugin.getLocale().newMessage("&7Syntax error...").sendPrefixedMessage(sender);
+            this.plugin.getLocale().newMessage("&7Syntax error...").sendPrefixedMessage(sender);
             return ReturnType.SYNTAX_ERROR;
         }
-        if (!Methods.isInt(args[1])) {
-            plugin.getLocale().newMessage("&6" + args[1] + " &7is not a number...").sendPrefixedMessage(sender);
+        if (!NumberUtils.isInt(args[1])) {
+            this.plugin.getLocale().newMessage("&6" + args[1] + " &7is not a number...").sendPrefixedMessage(sender);
             return ReturnType.SYNTAX_ERROR;
         }
 
@@ -36,7 +37,7 @@ public class CommandBoost extends AbstractCommand {
 
         if (args.length > 2) {
             for (String line : args) {
-                long time = Methods.parseTime(line);
+                long time = TimeUtils.parseTime(line);
                 duration += time;
 
             }
@@ -44,14 +45,14 @@ public class CommandBoost extends AbstractCommand {
 
         Player player = Bukkit.getPlayer(args[0]);
         if (player == null) {
-            plugin.getLocale().newMessage("&cThat player does not exist or is not online...").sendPrefixedMessage(sender);
+            this.plugin.getLocale().newMessage("&cThat player does not exist or is not online...").sendPrefixedMessage(sender);
             return ReturnType.FAILURE;
         }
 
         BoostData boostData = new BoostData(Integer.parseInt(args[1]), duration == 0L ? Long.MAX_VALUE : System.currentTimeMillis() + duration, player.getUniqueId());
-        plugin.getBoostManager().addBoostToPlayer(boostData);
-        plugin.getLocale().newMessage("&7Successfully boosted &6" + Bukkit.getPlayer(args[0]).getName()
-                + "'s &7hopper transfer rates by &6" + args[1] + "x" + (duration == 0L ? "" : (" for " + Methods.makeReadable(duration))) + "&7.").sendPrefixedMessage(sender);
+        this.plugin.getBoostManager().addBoostToPlayer(boostData);
+        this.plugin.getLocale().newMessage("&7Successfully boosted &6" + Bukkit.getPlayer(args[0]).getName()
+                + "'s &7hopper transfer rates by &6" + args[1] + "x" + (duration == 0L ? "" : (" for " + TimeUtils.makeReadable(duration))) + "&7.").sendPrefixedMessage(sender);
         return ReturnType.SUCCESS;
     }
 
@@ -68,7 +69,8 @@ public class CommandBoost extends AbstractCommand {
         } else if (args.length == 3) {
             return Arrays.asList("1m", "1h", "1d");
         }
-        return null;
+
+        return Collections.emptyList();
     }
 
     @Override

src/main/java/com/songoda/epichoppers/commands/CommandGive.java

@@ -12,7 +12,6 @@ import java.util.Arrays;
 import java.util.List;
 
 public class CommandGive extends AbstractCommand {
-
     private final EpicHoppers plugin;
 
     public CommandGive(EpicHoppers plugin) {
@@ -26,29 +25,29 @@ public class CommandGive extends AbstractCommand {
             return ReturnType.SYNTAX_ERROR;
         }
         if (Bukkit.getPlayerExact(args[0]) == null) {
-            plugin.getLocale().newMessage("&cThat username does not exist, or the user is not online!").sendPrefixedMessage(sender);
+            this.plugin.getLocale().newMessage("&cThat username does not exist, or the user is not online!").sendPrefixedMessage(sender);
             return ReturnType.FAILURE;
         }
 
-        Level level = plugin.getLevelManager().getLowestLevel();
+        Level level = this.plugin.getLevelManager().getLowestLevel();
         Player player;
         if (Bukkit.getPlayer(args[0]) == null) {
-            plugin.getLocale().newMessage("&cThat player does not exist or is currently offline.").sendPrefixedMessage(sender);
+            this.plugin.getLocale().newMessage("&cThat player does not exist or is currently offline.").sendPrefixedMessage(sender);
             return ReturnType.FAILURE;
         } else {
             player = Bukkit.getPlayer(args[0]);
         }
 
 
-        if (!plugin.getLevelManager().isLevel(Integer.parseInt(args[1]))) {
-            plugin.getLocale().newMessage("&cNot a valid level... The current valid levels are: &4" + level.getLevel() + "-" + plugin.getLevelManager().getHighestLevel().getLevel() + "&c.")
+        if (!this.plugin.getLevelManager().isLevel(Integer.parseInt(args[1]))) {
+            this.plugin.getLocale().newMessage("&cNot a valid level... The current valid levels are: &4" + level.getLevel() + "-" + this.plugin.getLevelManager().getHighestLevel().getLevel() + "&c.")
                     .sendPrefixedMessage(sender);
             return ReturnType.FAILURE;
         } else {
-            level = plugin.getLevelManager().getLevel(Integer.parseInt(args[1]));
+            level = this.plugin.getLevelManager().getLevel(Integer.parseInt(args[1]));
         }
-        player.getInventory().addItem(plugin.newHopperItem(level));
-        plugin.getLocale().getMessage("command.give.success").processPlaceholder("level", level.getLevel()).sendPrefixedMessage(player);
+        player.getInventory().addItem(this.plugin.newHopperItem(level));
+        this.plugin.getLocale().getMessage("command.give.success").processPlaceholder("level", level.getLevel()).sendPrefixedMessage(player);
 
         return ReturnType.SUCCESS;
     }

src/main/java/com/songoda/epichoppers/commands/CommandReload.java

@@ -7,7 +7,6 @@ import org.bukkit.command.CommandSender;
 import java.util.List;
 
 public class CommandReload extends AbstractCommand {
-
     private final EpicHoppers plugin;
 
     public CommandReload(EpicHoppers plugin) {
@@ -17,8 +16,8 @@ public class CommandReload extends AbstractCommand {
 
     @Override
     protected ReturnType runCommand(CommandSender sender, String... args) {
-        plugin.reloadConfig();
-        plugin.getLocale().getMessage("&7Configuration and Language files reloaded.").sendPrefixedMessage(sender);
+        this.plugin.reloadConfig();
+        this.plugin.getLocale().getMessage("&7Configuration and Language files reloaded.").sendPrefixedMessage(sender);
         return ReturnType.SUCCESS;
     }
 

src/main/java/com/songoda/epichoppers/commands/CommandSettings.java

@@ -9,7 +9,6 @@ import org.bukkit.entity.Player;
 import java.util.List;
 
 public class CommandSettings extends AbstractCommand {
-
     private final EpicHoppers plugin;
 
     public CommandSettings(EpicHoppers plugin) {
@@ -19,7 +18,7 @@ public class CommandSettings extends AbstractCommand {
 
     @Override
     protected ReturnType runCommand(CommandSender sender, String... args) {
-        plugin.getGuiManager().showGUI((Player) sender, new PluginConfigGui(plugin));
+        this.plugin.getGuiManager().showGUI((Player) sender, new PluginConfigGui(this.plugin));
         return ReturnType.SUCCESS;
     }
 

src/main/java/com/songoda/epichoppers/compatibility/EpicHoppersPermission.java

@@ -5,9 +5,7 @@ import com.songoda.skyblock.permission.BasicPermission;
 import com.songoda.skyblock.permission.PermissionType;
 
 public class EpicHoppersPermission extends BasicPermission {
-
     public EpicHoppersPermission() {
         super("EpicHoppers", CompatibleMaterial.HOPPER, PermissionType.GENERIC);
     }
-
 }

src/main/java/com/songoda/epichoppers/containers/ContainerManager.java

@@ -1,6 +1,5 @@
 package com.songoda.epichoppers.containers;
 
-import com.songoda.epichoppers.EpicHoppers;
 import com.songoda.epichoppers.containers.impl.AdvancedChestImplementation;
 import com.songoda.epichoppers.containers.impl.EpicFarmingImplementation;
 import com.songoda.epichoppers.containers.impl.FabledSkyBlockImplementation;
@@ -13,12 +12,9 @@ import java.util.HashSet;
 import java.util.Set;
 
 public class ContainerManager {
-
-    private final EpicHoppers plugin;
     private final Set<IContainer> customContainers;
 
-    public ContainerManager(EpicHoppers plugin) {
-        this.plugin = plugin;
+    public ContainerManager() {
         this.customContainers = new HashSet<>();
 
         registerCustomContainerImplementation("AdvancedChests", new AdvancedChestImplementation());
@@ -27,13 +23,13 @@ public class ContainerManager {
     }
 
     public Set<IContainer> getCustomContainerImplementations() {
-        return Collections.unmodifiableSet(customContainers);
+        return Collections.unmodifiableSet(this.customContainers);
     }
 
     public void registerCustomContainerImplementation(String requiredPlugin, IContainer container) {
         PluginManager pluginManager = Bukkit.getPluginManager();
         if (requiredPlugin != null && pluginManager.isPluginEnabled(requiredPlugin)) {
-            customContainers.add(container);
+            this.customContainers.add(container);
         }
     }
 
@@ -42,7 +38,7 @@ public class ContainerManager {
     }
 
     public CustomContainer getCustomContainer(Block block) {
-        for (IContainer container : customContainers) {
+        for (IContainer container : this.customContainers) {
             CustomContainer customContainer = container.getCustomContainer(block);
             if (customContainer.isContainer()) {
                 return customContainer;

src/main/java/com/songoda/epichoppers/containers/CustomContainer.java

@@ -4,14 +4,17 @@ import org.bukkit.block.Block;
 import org.bukkit.inventory.ItemStack;
 
 public abstract class CustomContainer {
-
     private final Block block;
+
     public CustomContainer(Block block) {
         this.block = block;
     }
 
     public abstract boolean addToContainer(ItemStack itemToMove);
+
     public abstract ItemStack[] getItems();
+
     public abstract void removeFromContainer(ItemStack itemToMove, int amountToMove);
+
     public abstract boolean isContainer();
 }

src/main/java/com/songoda/epichoppers/containers/IContainer.java

@@ -3,6 +3,5 @@ package com.songoda.epichoppers.containers;
 import org.bukkit.block.Block;
 
 public interface IContainer {
-
     CustomContainer getCustomContainer(Block block);
 }

src/main/java/com/songoda/epichoppers/containers/impl/AdvancedChestImplementation.java

@@ -8,13 +8,12 @@ import us.lynuxcraft.deadsilenceiv.advancedchests.AdvancedChestsAPI;
 import us.lynuxcraft.deadsilenceiv.advancedchests.chest.AdvancedChest;
 
 public class AdvancedChestImplementation implements IContainer {
-
     @Override
     public CustomContainer getCustomContainer(Block block) {
         return new Container(block);
     }
 
-    class Container extends CustomContainer {
+    static class Container extends CustomContainer {
         private final AdvancedChest advancedChest;
 
         public Container(Block block) {
@@ -24,23 +23,26 @@ public class AdvancedChestImplementation implements IContainer {
 
         @Override
         public boolean addToContainer(ItemStack itemToMove) {
-            return AdvancedChestsAPI.addItemToChest(advancedChest, itemToMove);
+            return AdvancedChestsAPI.addItemToChest(this.advancedChest, itemToMove);
         }
 
         @Override
         public ItemStack[] getItems() {
-            return advancedChest.getAllItems().toArray(new ItemStack[0]);
+            return this.advancedChest.getAllItems().toArray(new ItemStack[0]);
         }
 
         @Override
         public void removeFromContainer(ItemStack itemToMove, int amountToMove) {
-            for (ItemStack item : advancedChest.getAllItems()) {
-                if (item == null) return;
+            for (ItemStack item : this.advancedChest.getAllItems()) {
+                if (item == null) {
+                    return;
+                }
+
                 if (itemToMove.getType() == item.getType()) {
                     item.setAmount(item.getAmount() - amountToMove);
 
                     if (item.getAmount() <= 0)
-                        advancedChest.getAllItems().remove(item);
+                        this.advancedChest.getAllItems().remove(item);
                     return;
                 }
             }
@@ -48,7 +50,7 @@ public class AdvancedChestImplementation implements IContainer {
 
         @Override
         public boolean isContainer() {
-            return advancedChest != null;
+            return this.advancedChest != null;
         }
     }
 }

src/main/java/com/songoda/epichoppers/containers/impl/EpicFarmingImplementation.java

@@ -9,13 +9,12 @@ import org.bukkit.block.Block;
 import org.bukkit.inventory.ItemStack;
 
 public class EpicFarmingImplementation implements IContainer {
-
     @Override
     public CustomContainer getCustomContainer(Block block) {
         return new Container(block);
     }
 
-    class Container extends CustomContainer {
+    static class Container extends CustomContainer {
         private final Farm farm;
 
         public Container(Block block) {
@@ -25,28 +24,28 @@ public class EpicFarmingImplementation implements IContainer {
 
         @Override
         public boolean addToContainer(ItemStack itemToMove) {
-            if (!farm.willFit(itemToMove)) {
+            if (!this.farm.willFit(itemToMove)) {
                 return false;
             }
-            farm.addItem(itemToMove);
+            this.farm.addItem(itemToMove);
             return true;
         }
 
         @Override
         public ItemStack[] getItems() {
-            return farm.getItems()
-                    .stream().filter(i -> CompatibleMaterial.getMaterial(i) != CompatibleMaterial.BONE_MEAL)
+            return this.farm.getItems()
+                    .stream().filter(item -> CompatibleMaterial.getMaterial(item) != CompatibleMaterial.BONE_MEAL)
                     .toArray(ItemStack[]::new);
         }
 
         @Override
         public void removeFromContainer(ItemStack itemToMove, int amountToMove) {
-            farm.removeMaterial(itemToMove.getType(), amountToMove);
+            this.farm.removeMaterial(itemToMove.getType(), amountToMove);
         }
 
         @Override
         public boolean isContainer() {
-            return farm != null;
+            return this.farm != null;
         }
     }
 }

src/main/java/com/songoda/epichoppers/containers/impl/FabledSkyBlockImplementation.java

@@ -10,13 +10,12 @@ import org.bukkit.block.Block;
 import org.bukkit.inventory.ItemStack;
 
 public class FabledSkyBlockImplementation implements IContainer {
-
     @Override
     public CustomContainer getCustomContainer(Block block) {
         return new Container(block);
     }
 
-    class Container extends CustomContainer {
+    static class Container extends CustomContainer {
         private final Stackable stackable;
 
         public Container(Block block) {
@@ -30,13 +29,13 @@ public class FabledSkyBlockImplementation implements IContainer {
 
         @Override
         public boolean addToContainer(ItemStack itemToMove) {
-            if (CompatibleMaterial.getMaterial(itemToMove) != stackable.getMaterial()) {
+            if (CompatibleMaterial.getMaterial(itemToMove) != this.stackable.getMaterial()) {
                 return false;
             }
 
-            stackable.addOne();
-            if (stackable.getMaxSize() > 0 && stackable.isMaxSize()) {
-                stackable.setSize(stackable.getMaxSize());
+            this.stackable.addOne();
+            if (this.stackable.getMaxSize() > 0 && this.stackable.isMaxSize()) {
+                this.stackable.setSize(this.stackable.getMaxSize());
                 return false;
             }
 
@@ -45,22 +44,21 @@ public class FabledSkyBlockImplementation implements IContainer {
 
         @Override
         public ItemStack[] getItems() {
-            ItemStack[] array = { new ItemStack(stackable.getMaterial().getMaterial(), stackable.getSize()) };
-            return array;
+            return new ItemStack[]{new ItemStack(this.stackable.getMaterial().getMaterial(), this.stackable.getSize())};
         }
 
         @Override
         public void removeFromContainer(ItemStack itemToMove, int amountToMove) {
-            if (CompatibleMaterial.getMaterial(itemToMove) != stackable.getMaterial()) {
+            if (CompatibleMaterial.getMaterial(itemToMove) != this.stackable.getMaterial()) {
                 return;
             }
 
-            stackable.setSize(stackable.getSize() - amountToMove);
+            this.stackable.setSize(this.stackable.getSize() - amountToMove);
         }
 
         @Override
         public boolean isContainer() {
-            return stackable != null;
+            return this.stackable != null;
         }
     }
 }

src/main/java/com/songoda/epichoppers/database/DataManager.java

@@ -34,14 +34,13 @@ import java.util.UUID;
 import java.util.function.Consumer;
 
 public class DataManager extends DataManagerAbstract {
-
     public DataManager(DatabaseConnector databaseConnector, Plugin plugin) {
         super(databaseConnector, plugin);
     }
 
     public void createBoost(BoostData boostData) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String createBoostedPlayer = "INSERT INTO " + this.getTablePrefix() + "boosted_players (player, multiplier, end_time) VALUES (?, ?, ?)";
                 PreparedStatement statement = connection.prepareStatement(createBoostedPlayer);
                 statement.setString(1, boostData.getPlayer().toString());
@@ -57,7 +56,7 @@ public class DataManager extends DataManagerAbstract {
     public void getBoosts(Consumer<List<BoostData>> callback) {
         List<BoostData> boosts = new ArrayList<>();
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 Statement statement = connection.createStatement();
                 String selectBoostedPlayers = "SELECT * FROM " + this.getTablePrefix() + "boosted_players";
                 ResultSet result = statement.executeQuery(selectBoostedPlayers);
@@ -77,7 +76,7 @@ public class DataManager extends DataManagerAbstract {
 
     public void deleteBoost(BoostData boostData) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String deleteBoost = "DELETE FROM " + this.getTablePrefix() + "boosted_players WHERE end_time = ?";
                 PreparedStatement statement = connection.prepareStatement(deleteBoost);
                 statement.setLong(1, boostData.getEndTime());
@@ -90,7 +89,7 @@ public class DataManager extends DataManagerAbstract {
 
     public void createLink(Hopper hopper, Location location, LinkType type) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String createLink = "INSERT INTO " + this.getTablePrefix() + "links (hopper_id, link_type, world, x, y, z) VALUES (?, ?, ?, ?, ?, ?)";
                 PreparedStatement statement = connection.prepareStatement(createLink);
                 statement.setInt(1, hopper.getId());
@@ -110,7 +109,7 @@ public class DataManager extends DataManagerAbstract {
 
     public void updateItems(Hopper hopper, ItemType type, List<ItemStack> items) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String clearItems = "DELETE FROM " + this.getTablePrefix() + "items WHERE hopper_id = ? AND item_type = ?";
                 try (PreparedStatement statement = connection.prepareStatement(clearItems)) {
                     statement.setInt(1, hopper.getId());
@@ -143,7 +142,7 @@ public class DataManager extends DataManagerAbstract {
 
     public void deleteLink(Hopper hopper, Location location) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String deleteLink = "DELETE FROM " + this.getTablePrefix() + "links WHERE hopper_id = ? AND world = ? AND x = ? AND y = ? AND z = ?";
                 PreparedStatement statement = connection.prepareStatement(deleteLink);
                 statement.setInt(1, hopper.getId());
@@ -160,7 +159,7 @@ public class DataManager extends DataManagerAbstract {
 
     public void deleteLinks(Hopper hopper) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String deleteHopperLinks = "DELETE FROM " + this.getTablePrefix() + "links WHERE hopper_id = ?";
                 PreparedStatement statement = connection.prepareStatement(deleteHopperLinks);
                 statement.setInt(1, hopper.getId());
@@ -172,13 +171,14 @@ public class DataManager extends DataManagerAbstract {
     }
 
     public void createHoppers(List<Hopper> hoppers) {
-        for (Hopper hopper : hoppers)
+        for (Hopper hopper : hoppers) {
             createHopper(hopper);
+        }
     }
 
     public void createHopper(Hopper hopper) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String createHopper = "INSERT INTO " + this.getTablePrefix() + "placed_hoppers (level, placed_by, last_opened_by, teleport_trigger, world, x, y, z) VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
                 try (PreparedStatement statement = connection.prepareStatement(createHopper)) {
                     statement.setInt(1, hopper.getLevel().getLevel());
@@ -204,20 +204,25 @@ public class DataManager extends DataManagerAbstract {
                 Map<ItemStack, ItemType> items = new HashMap<>();
                 Filter filter = hopper.getFilter();
 
-                for (ItemStack item : filter.getWhiteList())
+                for (ItemStack item : filter.getWhiteList()) {
                     items.put(item, ItemType.WHITELIST);
+                }
 
-                for (ItemStack item : filter.getBlackList())
+                for (ItemStack item : filter.getBlackList()) {
                     items.put(item, ItemType.BLACKLIST);
+                }
 
-                for (ItemStack item : filter.getVoidList())
+                for (ItemStack item : filter.getVoidList()) {
                     items.put(item, ItemType.VOID);
+                }
 
-                for (ItemStack item : filter.getAutoSellWhiteList())
+                for (ItemStack item : filter.getAutoSellWhiteList()) {
                     items.put(item, ItemType.AUTO_SELL_WHITELIST);
+                }
 
-                for (ItemStack item : filter.getAutoSellBlackList())
+                for (ItemStack item : filter.getAutoSellBlackList()) {
                     items.put(item, ItemType.AUTO_SELL_BLACKLIST);
+                }
 
                 String createItem = "INSERT INTO " + this.getTablePrefix() + "items (hopper_id, item_type, item) VALUES (?, ?, ?)";
                 try (PreparedStatement statement = connection.prepareStatement(createItem)) {
@@ -239,11 +244,13 @@ public class DataManager extends DataManagerAbstract {
 
                 Map<Location, LinkType> links = new HashMap<>();
 
-                for (Location location : hopper.getLinkedBlocks())
+                for (Location location : hopper.getLinkedBlocks()) {
                     links.put(location, LinkType.REGULAR);
+                }
 
-                if (filter.getEndPoint() != null)
+                if (filter.getEndPoint() != null) {
                     links.put(filter.getEndPoint(), LinkType.REJECT);
+                }
 
                 String createLink = "INSERT INTO " + this.getTablePrefix() + "links (hopper_id, link_type, world, x, y, z) VALUES (?, ?, ?, ?, ?, ?)";
                 try (PreparedStatement statement = connection.prepareStatement(createLink)) {
@@ -269,7 +276,7 @@ public class DataManager extends DataManagerAbstract {
 
     public void updateHopper(Hopper hopper) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String updateHopper = "UPDATE " + this.getTablePrefix() + "placed_hoppers SET level = ?, placed_by = ?, last_opened_by = ?, teleport_trigger = ? WHERE id = ?";
                 PreparedStatement statement = connection.prepareStatement(updateHopper);
                 statement.setInt(1, hopper.getLevel().getLevel());
@@ -286,7 +293,7 @@ public class DataManager extends DataManagerAbstract {
 
     public void deleteHopper(Hopper hopper) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 String deleteHopper = "DELETE FROM " + this.getTablePrefix() + "placed_hoppers WHERE id = ?";
                 try (PreparedStatement statement = connection.prepareStatement(deleteHopper)) {
                     statement.setInt(1, hopper.getId());
@@ -312,7 +319,7 @@ public class DataManager extends DataManagerAbstract {
 
     public void getHoppers(Consumer<Map<Integer, Hopper>> callback) {
         this.runAsync(() -> {
-            try (Connection connection = this.databaseConnector.getConnection()){
+            try (Connection connection = this.databaseConnector.getConnection()) {
                 Map<Integer, Hopper> hoppers = new HashMap<>();
 
                 try (Statement statement = connection.createStatement()) {
@@ -321,8 +328,9 @@ public class DataManager extends DataManagerAbstract {
                     while (result.next()) {
                         World world = Bukkit.getWorld(result.getString("world"));
 
-                        if (world == null)
+                        if (world == null) {
                             continue;
+                        }
 
                         int id = result.getInt("id");
                         int level = result.getInt("level");
@@ -342,7 +350,7 @@ public class DataManager extends DataManagerAbstract {
 
                         Hopper hopper = new HopperBuilder(location)
                                 .setId(id)
-                                .setLevel(EpicHoppers.getInstance().getLevelManager().getLevel(level))
+                                .setLevel(((EpicHoppers) this.plugin).getLevelManager().getLevel(level))
                                 .setPlacedBy(placedBy)
                                 .setLastPlayerOpened(lastOpenedBy)
                                 .setTeleportTrigger(teleportTrigger)
@@ -358,8 +366,9 @@ public class DataManager extends DataManagerAbstract {
                     while (result.next()) {
                         World world = Bukkit.getWorld(result.getString("world"));
 
-                        if (world == null)
+                        if (world == null) {
                             continue;
+                        }
 
                         int id = result.getInt("hopper_id");
                         LinkType type = LinkType.valueOf(result.getString("link_type"));
@@ -370,7 +379,9 @@ public class DataManager extends DataManagerAbstract {
                         Location location = new Location(world, x, y, z);
 
                         Hopper hopper = hoppers.get(id);
-                        if (hopper == null) break;
+                        if (hopper == null) {
+                            break;
+                        }
 
                         hopper.addLinkedBlock(location, type);
                     }
@@ -392,10 +403,13 @@ public class DataManager extends DataManagerAbstract {
                         }
 
                         Hopper hopper = hoppers.get(id);
-                        if (hopper == null) break;
+                        if (hopper == null) {
+                            break;
+                        }
 
-                        if (item != null)
+                        if (item != null) {
                             hopper.getFilter().addItem(item, type);
+                        }
                     }
                 }
                 this.sync(() -> callback.accept(hoppers));

src/main/java/com/songoda/epichoppers/database/migrations/_1_InitialMigration.java

@@ -9,14 +9,16 @@ import java.sql.SQLException;
 import java.sql.Statement;
 
 public class _1_InitialMigration extends DataMigration {
+    private final EpicHoppers plugin;
 
-    public _1_InitialMigration() {
+    public _1_InitialMigration(EpicHoppers plugin) {
         super(1);
+        this.plugin = plugin;
     }
 
     @Override
     public void migrate(Connection connection, String tablePrefix) throws SQLException {
-        String autoIncrement = EpicHoppers.getInstance().getDatabaseConnector() instanceof MySQLConnector ? " AUTO_INCREMENT" : "";
+        String autoIncrement = this.plugin.getDatabaseConnector() instanceof MySQLConnector ? " AUTO_INCREMENT" : "";
 
         // Create hoppers table
         try (Statement statement = connection.createStatement()) {

src/main/java/com/songoda/epichoppers/gui/GUIAutoSellFilter.java

@@ -18,7 +18,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class GUIAutoSellFilter extends CustomizableGui {
-    private static final List<GUIAutoSellFilter> openInventories = new ArrayList<>();
+    private static final List<GUIAutoSellFilter> OPEN_INVENTORIES = new ArrayList<>();
 
     private final EpicHoppers plugin;
     private final Hopper hopper;
@@ -36,10 +36,10 @@ public class GUIAutoSellFilter extends CustomizableGui {
         setDefaultItem(null);
         setAcceptsItems(true);
 
-        setOnOpen((event) -> GUIAutoSellFilter.openInventories.add(this));
+        setOnOpen((event) -> GUIAutoSellFilter.OPEN_INVENTORIES.add(this));
 
         setOnClose((event) -> {
-            GUIAutoSellFilter.openInventories.remove(this);
+            GUIAutoSellFilter.OPEN_INVENTORIES.remove(this);
             hopper.setActivePlayer(null);
             compile();
         });
@@ -63,7 +63,7 @@ public class GUIAutoSellFilter extends CustomizableGui {
         setButton("back", 8, GuiUtils.createButtonItem(CompatibleMaterial.ARROW.getItem(),
                         plugin.getLocale().getMessage("general.nametag.back").getMessage()),
                 (event) -> {
-                    hopper.overview(guiManager, event.player);
+                    hopper.overview(this.guiManager, event.player);
                     compile();
                 });
 
@@ -80,8 +80,10 @@ public class GUIAutoSellFilter extends CustomizableGui {
 
         int num = 0;
         for (ItemStack m : filter.getAutoSellWhiteList()) {
-            if (num >= filter.getAutoSellWhiteList().size()) break;
-            setItem(whiteListSlots[num], new ItemStack(m));
+            if (num >= filter.getAutoSellWhiteList().size()) {
+                break;
+            }
+            setItem(this.whiteListSlots[num], new ItemStack(m));
             num++;
         }
 
@@ -98,8 +100,10 @@ public class GUIAutoSellFilter extends CustomizableGui {
 
         num = 0;
         for (ItemStack m : filter.getAutoSellBlackList()) {
-            if (num >= filter.getAutoSellBlackList().size()) break;
-            setItem(blackListSlots[num], new ItemStack(m));
+            if (num >= filter.getAutoSellBlackList().size()) {
+                break;
+            }
+            setItem(this.blackListSlots[num], new ItemStack(m));
             num++;
         }
 
@@ -109,7 +113,11 @@ public class GUIAutoSellFilter extends CustomizableGui {
 
         indicatorMeta.setDisplayName(plugin.getLocale().getMessage("interface.autosell-filter.infotitle").getMessage());
         ArrayList<String> loreInfo = new ArrayList<>();
-        String[] parts = plugin.getLocale().getMessage("interface.autosell-filter.infolore").getMessage().split("\\|");
+        String[] parts = plugin
+                .getLocale()
+                .getMessage("interface.autosell-filter.infolore")
+                .getMessage()
+                .split("\\|");
 
         for (String line : parts) {
             loreInfo.add(TextUtils.formatText(line));
@@ -127,22 +135,24 @@ public class GUIAutoSellFilter extends CustomizableGui {
     }
 
     private void compile() {
-        ItemStack[] items = inventory.getContents();
+        ItemStack[] items = this.inventory.getContents();
 
-        Filter filter = hopper.getFilter();
+        Filter filter = this.hopper.getFilter();
 
         List<ItemStack> whiteListItems = new ArrayList<>();
         List<ItemStack> blackListItems = new ArrayList<>();
 
         for (int i = 0; i < items.length; i++) {
-            for (int slot : whiteListSlots) {
-                if (slot != i) continue;
+            for (int slot : this.whiteListSlots) {
+                if (slot != i) {
+                    continue;
+                }
 
                 if (items[i] != null && !items[i].getType().isAir()) {
                     ItemStack item = items[i];
                     if (item.getAmount() != 1) {
                         item.setAmount(item.getAmount() - 1);
-                        Bukkit.getPlayer(hopper.getLastPlayerOpened()).getInventory().addItem(item);
+                        Bukkit.getPlayer(this.hopper.getLastPlayerOpened()).getInventory().addItem(item);
                         item.setAmount(1);
                     }
 
@@ -150,14 +160,16 @@ public class GUIAutoSellFilter extends CustomizableGui {
                 }
             }
 
-            for (int slot : blackListSlots) {
-                if (slot != i) continue;
+            for (int slot : this.blackListSlots) {
+                if (slot != i) {
+                    continue;
+                }
 
                 if (items[i] != null && !items[i].getType().isAir()) {
                     ItemStack item = items[i];
                     if (item.getAmount() != 1) {
                         item.setAmount(item.getAmount() - 1);
-                        Bukkit.getPlayer(hopper.getLastPlayerOpened()).getInventory().addItem(item);
+                        Bukkit.getPlayer(this.hopper.getLastPlayerOpened()).getInventory().addItem(item);
                         item.setAmount(1);
                     }
                     blackListItems.add(item);
@@ -167,12 +179,12 @@ public class GUIAutoSellFilter extends CustomizableGui {
 
         filter.setAutoSellWhiteList(whiteListItems);
         filter.setAutoSellBlackList(blackListItems);
-        plugin.getDataManager().updateItems(hopper, ItemType.AUTO_SELL_WHITELIST, whiteListItems);
-        plugin.getDataManager().updateItems(hopper, ItemType.AUTO_SELL_BLACKLIST, blackListItems);
+        this.plugin.getDataManager().updateItems(this.hopper, ItemType.AUTO_SELL_WHITELIST, whiteListItems);
+        this.plugin.getDataManager().updateItems(this.hopper, ItemType.AUTO_SELL_BLACKLIST, blackListItems);
     }
 
     public static void compileOpenAutoSellFilter(Hopper hopper) {
-        for (GUIAutoSellFilter autoSellFilter : openInventories) {
+        for (GUIAutoSellFilter autoSellFilter : OPEN_INVENTORIES) {
             if (autoSellFilter.hopper == hopper) {
                 autoSellFilter.compile();
             }

src/main/java/com/songoda/epichoppers/gui/GUICrafting.java

@@ -13,9 +13,8 @@ import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 
 public class GUICrafting extends CustomizableGui {
-
-    public GUICrafting(ModuleAutoCrafting module, Hopper hopper, Player player) {
-        super(EpicHoppers.getInstance(), "crafting");
+    public GUICrafting(ModuleAutoCrafting module, EpicHoppers plugin, Hopper hopper, Player player) {
+        super(plugin, "crafting");
         setRows(3);
         setTitle(Methods.formatName(hopper.getLevel().getLevel()) + TextUtils.formatText(" &8-&f Crafting"));
         setOnClose((event) -> {
@@ -37,20 +36,20 @@ public class GUICrafting extends CustomizableGui {
         mirrorFill("mirrorfill_5", 1, 1, false, true, glass3);
 
         setButton("back", 8, GuiUtils.createButtonItem(CompatibleMaterial.ARROW.getItem(),
-                EpicHoppers.getInstance().getLocale().getMessage("general.nametag.back").getMessage()),
+                        plugin.getLocale().getMessage("general.nametag.back").getMessage()),
                 (event) -> {
-                    hopper.overview(guiManager, event.player);
+                    hopper.overview(this.guiManager, event.player);
                     setItem(module, hopper, player);
                 }
         );
 
         setButton(13, module.getAutoCrafting(hopper),
-                (event) -> module.setAutoCrafting(hopper, player, inventory.getItem(13)));
+                (event) -> module.setAutoCrafting(hopper, player, this.inventory.getItem(13)));
 
         setUnlocked(13);
     }
 
     public void setItem(ModuleAutoCrafting module, Hopper hopper, Player player) {
-        module.setAutoCrafting(hopper, player, inventory.getItem(13));
+        module.setAutoCrafting(hopper, player, this.inventory.getItem(13));
     }
 }

src/main/java/com/songoda/epichoppers/gui/GUIFilter.java

@@ -22,10 +22,9 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class GUIFilter extends CustomizableGui {
-    private static final List<GUIFilter> openInventories = new ArrayList<>();
+    private static final List<GUIFilter> OPEN_INVENTORIES = new ArrayList<>();
 
     private final EpicHoppers plugin;
-
     private final Hopper hopper;
 
     public GUIFilter(EpicHoppers plugin, Hopper hopper, Player player) {
@@ -38,10 +37,10 @@ public class GUIFilter extends CustomizableGui {
         setDefaultItem(null);
         setAcceptsItems(true);
 
-        setOnOpen((event) -> GUIFilter.openInventories.add(this));
+        setOnOpen((event) -> GUIFilter.OPEN_INVENTORIES.add(this));
 
         setOnClose((event) -> {
-            GUIFilter.openInventories.remove(this);
+            GUIFilter.OPEN_INVENTORIES.remove(this);
             hopper.setActivePlayer(null);
             compile();
         });
@@ -66,9 +65,9 @@ public class GUIFilter extends CustomizableGui {
         it.setItemMeta(itm);
 
         setButton("back", 8, GuiUtils.createButtonItem(CompatibleMaterial.ARROW.getItem(),
-                plugin.getLocale().getMessage("general.nametag.back").getMessage()),
+                        plugin.getLocale().getMessage("general.nametag.back").getMessage()),
                 (event) -> {
-                    hopper.overview(guiManager, event.player);
+                    hopper.overview(this.guiManager, event.player);
                     compile();
                 });
 
@@ -80,7 +79,9 @@ public class GUIFilter extends CustomizableGui {
         int[] awhite = {9, 10, 18, 19, 27, 28, 36, 37};
         int num = 0;
         for (ItemStack m : filter.getWhiteList()) {
-            if (num >= filter.getWhiteList().size()) break;
+            if (num >= filter.getWhiteList().size()) {
+                break;
+            }
             setItem(awhite[num], new ItemStack(m));
             num++;
         }
@@ -98,7 +99,10 @@ public class GUIFilter extends CustomizableGui {
         int[] ablack = {11, 12, 20, 21, 29, 30, 38, 39};
         num = 0;
         for (ItemStack m : filter.getBlackList()) {
-            if (num >= filter.getBlackList().size()) break;
+            if (num >= filter.getBlackList().size()) {
+                break;
+            }
+
             setItem(ablack[num], new ItemStack(m));
             num++;
         }
@@ -116,37 +120,39 @@ public class GUIFilter extends CustomizableGui {
         int[] voidSlots = {13, 14, 22, 23, 31, 32, 40, 41};
         num = 0;
         for (ItemStack m : filter.getVoidList()) {
-            if (num >= filter.getVoidList().size()) break;
+            if (num >= filter.getVoidList().size()) {
+                break;
+            }
             setItem(voidSlots[num], new ItemStack(m));
             num++;
         }
 
         ItemStack itemInfo = new ItemStack(CompatibleMaterial.PAPER.getMaterial());
-        ItemMeta itemmetaInfo = itemInfo.getItemMeta();
-        itemmetaInfo.setDisplayName(plugin.getLocale().getMessage("interface.filter.infotitle").getMessage());
+        ItemMeta itemMetaInfo = itemInfo.getItemMeta();
+        itemMetaInfo.setDisplayName(plugin.getLocale().getMessage("interface.filter.infotitle").getMessage());
         ArrayList<String> loreInfo = new ArrayList<>();
         String[] parts = plugin.getLocale().getMessage("interface.filter.infolore").getMessage().split("\\|");
         for (String line : parts) {
             loreInfo.add(TextUtils.formatText(line));
         }
-        itemmetaInfo.setLore(loreInfo);
-        itemInfo.setItemMeta(itemmetaInfo);
+        itemMetaInfo.setLore(loreInfo);
+        itemInfo.setItemMeta(itemMetaInfo);
 
         setItem("info", 16, itemInfo);
 
 
         ItemStack hook = new ItemStack(CompatibleMaterial.TRIPWIRE_HOOK.getMaterial());
-        ItemMeta hookmeta = hook.getItemMeta();
-        hookmeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.rejectsync").getMessage());
-        ArrayList<String> lorehook = new ArrayList<>();
+        ItemMeta hookMeta = hook.getItemMeta();
+        hookMeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.rejectsync").getMessage());
+        ArrayList<String> loreHook = new ArrayList<>();
         parts = plugin.getLocale().getMessage("interface.hopper.synclore")
                 .processPlaceholder("amount", filter.getEndPoint() != null ? 1 : 0)
                 .getMessage().split("\\|");
         for (String line : parts) {
-            lorehook.add(TextUtils.formatText(line));
+            loreHook.add(TextUtils.formatText(line));
         }
-        hookmeta.setLore(lorehook);
-        hook.setItemMeta(hookmeta);
+        hookMeta.setLore(loreHook);
+        hook.setItemMeta(hookMeta);
         setButton("reject", 43, hook,
                 (event) -> {
                     if (event.clickType == ClickType.RIGHT) {
@@ -167,9 +173,9 @@ public class GUIFilter extends CustomizableGui {
     }
 
     private void compile() {
-        ItemStack[] items = inventory.getContents();
+        ItemStack[] items = this.inventory.getContents();
 
-        Filter filter = hopper.getFilter();
+        Filter filter = this.hopper.getFilter();
 
         List<ItemStack> owhite = new ArrayList<>();
         List<ItemStack> oblack = new ArrayList<>();
@@ -181,36 +187,42 @@ public class GUIFilter extends CustomizableGui {
 
         for (int i = 0; i < items.length; i++) {
             for (int aa : awhite) {
-                if (aa != i) continue;
+                if (aa != i) {
+                    continue;
+                }
                 if (items[i] != null && items[i].getType() != Material.AIR) {
                     ItemStack item = items[i];
                     if (item.getAmount() != 1) {
                         item.setAmount(item.getAmount() - 1);
-                        Bukkit.getPlayer(hopper.getLastPlayerOpened()).getInventory().addItem(item);
+                        Bukkit.getPlayer(this.hopper.getLastPlayerOpened()).getInventory().addItem(item);
                         item.setAmount(1);
                     }
                     owhite.add(item);
                 }
             }
             for (int aa : ablack) {
-                if (aa != i) continue;
+                if (aa != i) {
+                    continue;
+                }
                 if (items[i] != null && items[i].getType() != Material.AIR) {
                     ItemStack item = items[i];
                     if (item.getAmount() != 1) {
                         item.setAmount(item.getAmount() - 1);
-                        Bukkit.getPlayer(hopper.getLastPlayerOpened()).getInventory().addItem(item);
+                        Bukkit.getPlayer(this.hopper.getLastPlayerOpened()).getInventory().addItem(item);
                         item.setAmount(1);
                     }
                     oblack.add(item);
                 }
             }
             for (int aa : avoid) {
-                if (aa != i) continue;
+                if (aa != i) {
+                    continue;
+                }
                 if (items[i] != null && items[i].getType() != Material.AIR) {
                     ItemStack item = items[i];
                     if (item.getAmount() != 1) {
                         item.setAmount(item.getAmount() - 1);
-                        Bukkit.getPlayer(hopper.getLastPlayerOpened()).getInventory().addItem(item);
+                        Bukkit.getPlayer(this.hopper.getLastPlayerOpened()).getInventory().addItem(item);
                         item.setAmount(1);
                     }
                     ovoid.add(item);
@@ -220,13 +232,13 @@ public class GUIFilter extends CustomizableGui {
         filter.setWhiteList(owhite);
         filter.setBlackList(oblack);
         filter.setVoidList(ovoid);
-        plugin.getDataManager().updateItems(hopper, ItemType.WHITELIST, owhite);
-        plugin.getDataManager().updateItems(hopper, ItemType.BLACKLIST, oblack);
-        plugin.getDataManager().updateItems(hopper, ItemType.VOID, ovoid);
+        this.plugin.getDataManager().updateItems(this.hopper, ItemType.WHITELIST, owhite);
+        this.plugin.getDataManager().updateItems(this.hopper, ItemType.BLACKLIST, oblack);
+        this.plugin.getDataManager().updateItems(this.hopper, ItemType.VOID, ovoid);
     }
 
     public static void compileOpenGuiFilter(Hopper hopper) {
-        for (GUIFilter guiFilter : openInventories) {
+        for (GUIFilter guiFilter : OPEN_INVENTORIES) {
             if (guiFilter.hopper == hopper) {
                 guiFilter.compile();
             }

src/main/java/com/songoda/epichoppers/gui/GUIOverview.java

@@ -4,17 +4,19 @@ import com.songoda.core.compatibility.CompatibleMaterial;
 import com.songoda.core.compatibility.ServerVersion;
 import com.songoda.core.gui.CustomizableGui;
 import com.songoda.core.gui.GuiUtils;
+import com.songoda.core.utils.NumberUtils;
 import com.songoda.core.utils.TextUtils;
+import com.songoda.core.utils.TimeUtils;
 import com.songoda.epichoppers.EpicHoppers;
 import com.songoda.epichoppers.boost.BoostData;
 import com.songoda.epichoppers.hopper.Hopper;
 import com.songoda.epichoppers.hopper.levels.Level;
 import com.songoda.epichoppers.hopper.levels.modules.Module;
+import com.songoda.epichoppers.hopper.teleport.TeleportTrigger;
 import com.songoda.epichoppers.player.SyncType;
 import com.songoda.epichoppers.settings.Settings;
 import com.songoda.epichoppers.utils.CostType;
 import com.songoda.epichoppers.utils.Methods;
-import com.songoda.epichoppers.hopper.teleport.TeleportTrigger;
 import org.bukkit.Bukkit;
 import org.bukkit.Material;
 import org.bukkit.entity.Player;
@@ -29,7 +31,6 @@ import java.util.Map;
 import java.util.stream.Collectors;
 
 public class GUIOverview extends CustomizableGui {
-
     private final EpicHoppers plugin;
     private final Hopper hopper;
     private final Player player;
@@ -48,7 +49,7 @@ public class GUIOverview extends CustomizableGui {
         constructGUI();
         this.setOnClose(action -> {
             hopper.setActivePlayer(null);
-            Bukkit.getScheduler().cancelTask(task);
+            Bukkit.getScheduler().cancelTask(this.task);
         });
     }
 
@@ -65,78 +66,84 @@ public class GUIOverview extends CustomizableGui {
         mirrorFill("mirrorfill_4", 1, 0, false, true, glass2);
         mirrorFill("mirrorfill_5", 1, 1, false, true, glass3);
 
-        plugin.getPlayerDataManager().getPlayerData(player).setLastHopper(hopper);
+        this.plugin.getPlayerDataManager().getPlayerData(this.player).setLastHopper(this.hopper);
 
-        Level level = hopper.getLevel();
+        Level level = this.hopper.getLevel();
 
-        Level nextLevel = plugin.getLevelManager().getHighestLevel().getLevel() > level.getLevel() ? plugin.getLevelManager().getLevel(level.getLevel() + 1) : null;
+        Level nextLevel = this.plugin.getLevelManager().getHighestLevel().getLevel() > level.getLevel() ? this.plugin.getLevelManager().getLevel(level.getLevel() + 1) : null;
 
-        ItemStack perl = new ItemStack(Material.ENDER_PEARL, 1);
-        ItemMeta perlmeta = perl.getItemMeta();
-        perlmeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.perltitle").getMessage());
-        ArrayList<String> loreperl = new ArrayList<>();
-        String[] parts = plugin.getLocale().getMessage("interface.hopper.perllore2")
-                .processPlaceholder("type", hopper.getTeleportTrigger() == TeleportTrigger.DISABLED
-                        ? plugin.getLocale().getMessage("general.word.disabled").getMessage()
-                        : hopper.getTeleportTrigger().name()).getMessage().split("\\|");
+        ItemStack pearl = new ItemStack(Material.ENDER_PEARL, 1);
+        ItemMeta pearlMeta = pearl.getItemMeta();
+        pearlMeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.perltitle").getMessage());
+        ArrayList<String> lorePearl = new ArrayList<>();
+        String[] parts = this.plugin.getLocale().getMessage("interface.hopper.perllore2")
+                .processPlaceholder(
+                        "type",
+                        this.hopper.getTeleportTrigger() == TeleportTrigger.DISABLED
+                                ? this.plugin.getLocale().getMessage("general.word.disabled").getMessage()
+                                : this.hopper.getTeleportTrigger().name()
+                )
+                .getMessage()
+                .split("\\|");
         for (String line : parts) {
-            loreperl.add(TextUtils.formatText(line));
+            lorePearl.add(TextUtils.formatText(line));
         }
-        perlmeta.setLore(loreperl);
-        perl.setItemMeta(perlmeta);
+        pearlMeta.setLore(lorePearl);
+        pearl.setItemMeta(pearlMeta);
 
         ItemStack filter = new ItemStack(ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13) ? Material.COMPARATOR : Material.valueOf("REDSTONE_COMPARATOR"), 1);
-        ItemMeta filtermeta = filter.getItemMeta();
-        filtermeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.filtertitle").getMessage());
-        ArrayList<String> lorefilter = new ArrayList<>();
-        parts = plugin.getLocale().getMessage("interface.hopper.filterlore").getMessage().split("\\|");
+        ItemMeta filterMeta = filter.getItemMeta();
+        filterMeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.filtertitle").getMessage());
+        ArrayList<String> loreFilter = new ArrayList<>();
+        parts = this.plugin.getLocale().getMessage("interface.hopper.filterlore").getMessage().split("\\|");
         for (String line : parts) {
-            lorefilter.add(TextUtils.formatText(line));
+            loreFilter.add(TextUtils.formatText(line));
         }
-        filtermeta.setLore(lorefilter);
-        filter.setItemMeta(filtermeta);
+        filterMeta.setLore(loreFilter);
+        filter.setItemMeta(filterMeta);
 
 
         ItemStack item = new ItemStack(Material.HOPPER, 1);
         ItemMeta itemmeta = item.getItemMeta();
-        itemmeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.currentlevel").processPlaceholder("level", level.getLevel()).getMessage());
+        itemmeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.currentlevel").processPlaceholder("level", level.getLevel()).getMessage());
         List<String> lore = level.getDescription();
-        if (plugin.getConfig().getBoolean("Main.Allow hopper Upgrading")) {
+        if (this.plugin.getConfig().getBoolean("Main.Allow hopper Upgrading")) {
             lore.add("");
-            if (nextLevel == null)
-                lore.add(plugin.getLocale().getMessage("interface.hopper.alreadymaxed").getMessage());
-            else {
-                lore.add(plugin.getLocale().getMessage("interface.hopper.nextlevel").processPlaceholder("level", nextLevel.getLevel()).getMessage());
+            if (nextLevel == null) {
+                lore.add(this.plugin.getLocale().getMessage("interface.hopper.alreadymaxed").getMessage());
+            } else {
+                lore.add(this.plugin.getLocale().getMessage("interface.hopper.nextlevel").processPlaceholder("level", nextLevel.getLevel()).getMessage());
                 lore.addAll(nextLevel.getDescription());
             }
         }
 
-        BoostData boostData = plugin.getBoostManager().getBoost(hopper.getPlacedBy());
+        BoostData boostData = this.plugin.getBoostManager().getBoost(this.hopper.getPlacedBy());
         if (boostData != null) {
-            parts = plugin.getLocale().getMessage("interface.hopper.boostedstats")
+            parts = this.plugin.getLocale().getMessage("interface.hopper.boostedstats")
                     .processPlaceholder("amount", Integer.toString(boostData.getMultiplier()))
-                    .processPlaceholder("time", Methods.makeReadable(boostData.getEndTime() - System.currentTimeMillis()))
+                    .processPlaceholder("time", TimeUtils.makeReadable(boostData.getEndTime() - System.currentTimeMillis()))
                     .getMessage().split("\\|");
             lore.add("");
-            for (String line : parts)
+            for (String line : parts) {
                 lore.add(TextUtils.formatText(line));
+            }
         }
 
         itemmeta.setLore(lore);
         item.setItemMeta(itemmeta);
 
         ItemStack hook = new ItemStack(Material.TRIPWIRE_HOOK, 1);
-        ItemMeta hookmeta = hook.getItemMeta();
-        hookmeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.synchopper").getMessage());
-        ArrayList<String> lorehook = new ArrayList<>();
-        parts = plugin.getLocale().getMessage("interface.hopper.synclore")
-                .processPlaceholder("amount", hopper.getLinkedBlocks().stream().distinct().count())
+        ItemMeta hookMeta = hook.getItemMeta();
+        hookMeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.synchopper").getMessage());
+        ArrayList<String> loreHook = new ArrayList<>();
+        parts = this.plugin.getLocale().getMessage("interface.hopper.synclore")
+                .processPlaceholder("amount", this.hopper.getLinkedBlocks().stream().distinct().count())
                 .getMessage().split("\\|");
         for (String line : parts) {
-            lorehook.add(TextUtils.formatText(line));
+            loreHook.add(TextUtils.formatText(line));
         }
-        hookmeta.setLore(lorehook);
-        hook.setItemMeta(hookmeta);
+        hookMeta.setLore(loreHook);
+        hook.setItemMeta(hookMeta);
 
         Map<Integer, Integer[]> layouts = new HashMap<>();
         layouts.put(1, new Integer[]{22});
@@ -152,13 +159,19 @@ public class GUIOverview extends CustomizableGui {
 
         int amount = 1;
 
-        boolean canFilter = level.isFilter() || player.hasPermission("EpicHoppers.Filter");
-        boolean canTeleport = level.isTeleport() || player.hasPermission("EpicHoppers.Teleport");
-        if (canFilter) amount++;
-        if (canTeleport) amount++;
+        boolean canFilter = level.isFilter() || this.player.hasPermission("EpicHoppers.Filter");
+        boolean canTeleport = level.isTeleport() || this.player.hasPermission("EpicHoppers.Teleport");
+        if (canFilter) {
+            amount++;
+        }
+        if (canTeleport) {
+            amount++;
+        }
 
-        List<Module> modules = level.getRegisteredModules().stream().filter(module ->
-                module.getGUIButton(hopper) != null).collect(Collectors.toList());
+        List<Module> modules = level.getRegisteredModules()
+                .stream()
+                .filter(module -> module.getGUIButton(this.hopper) != null)
+                .collect(Collectors.toList());
 
         amount += modules.size();
 
@@ -170,107 +183,111 @@ public class GUIOverview extends CustomizableGui {
             if (ii == 0) {
                 setButton("sync", slot, hook,
                         (event) -> {
-                            if (hopper.getLastPlayerOpened() != null && !hopper.getLastPlayerOpened().equals(player.getUniqueId())) {
-                                plugin.getLocale().getMessage("event.hopper.syncdidnotplace").sendPrefixedMessage(player);
+                            if (this.hopper.getLastPlayerOpened() != null && !this.hopper.getLastPlayerOpened().equals(this.player.getUniqueId())) {
+                                this.plugin.getLocale().getMessage("event.hopper.syncdidnotplace").sendPrefixedMessage(this.player);
                                 return;
                             }
-                            hopper.clearLinkedBlocks();
-                            plugin.getDataManager().deleteLinks(hopper);
+                            this.hopper.clearLinkedBlocks();
+                            this.plugin.getDataManager().deleteLinks(this.hopper);
                             if (event.clickType == ClickType.RIGHT) {
-                                plugin.getLocale().getMessage("event.hopper.desync").sendPrefixedMessage(player);
+                                this.plugin.getLocale().getMessage("event.hopper.desync").sendPrefixedMessage(this.player);
                                 constructGUI();
                                 return;
                             } else {
-                                plugin.getPlayerDataManager().getPlayerData(player).setSyncType(SyncType.REGULAR);
-                                plugin.getLocale().getMessage("event.hopper.syncnext").sendPrefixedMessage(player);
+                                this.plugin.getPlayerDataManager().getPlayerData(this.player).setSyncType(SyncType.REGULAR);
+                                this.plugin.getLocale().getMessage("event.hopper.syncnext").sendPrefixedMessage(this.player);
 
-                                if (level.getLinkAmount() > 1)
-                                    plugin.getLocale().getMessage("event.hopper.syncstart")
+                                if (level.getLinkAmount() > 1) {
+                                    this.plugin.getLocale().getMessage("event.hopper.syncstart")
                                             .processPlaceholder("amount", level.getLinkAmount())
-                                            .sendPrefixedMessage(player);
+                                            .sendPrefixedMessage(this.player);
+                                }
 
-                                hopper.timeout(player);
+                                this.hopper.timeout(this.player);
                             }
-                            player.closeInventory();
+                            this.player.closeInventory();
                         });
             } else if (canTeleport) {
-                setButton("teleport", slot, perl,
+                setButton("teleport", slot, pearl,
                         (event) -> {
                             if (event.clickType == ClickType.LEFT) {
-                                if (hopper.getLinkedBlocks() != null) {
-                                    plugin.getTeleportHandler().tpEntity(player, hopper);
-                                    player.closeInventory();
+                                if (this.hopper.getLinkedBlocks() != null) {
+                                    this.plugin.getTeleportHandler().tpEntity(this.player, this.hopper);
+                                    this.player.closeInventory();
                                 }
                             } else {
-                                if (hopper.getTeleportTrigger() == TeleportTrigger.DISABLED) {
-                                    hopper.setTeleportTrigger(TeleportTrigger.SNEAK);
-                                } else if (hopper.getTeleportTrigger() == TeleportTrigger.SNEAK) {
-                                    hopper.setTeleportTrigger(TeleportTrigger.WALK_ON);
-                                } else if (hopper.getTeleportTrigger() == TeleportTrigger.WALK_ON) {
-                                    hopper.setTeleportTrigger(TeleportTrigger.DISABLED);
+                                if (this.hopper.getTeleportTrigger() == TeleportTrigger.DISABLED) {
+                                    this.hopper.setTeleportTrigger(TeleportTrigger.SNEAK);
+                                } else if (this.hopper.getTeleportTrigger() == TeleportTrigger.SNEAK) {
+                                    this.hopper.setTeleportTrigger(TeleportTrigger.WALK_ON);
+                                } else if (this.hopper.getTeleportTrigger() == TeleportTrigger.WALK_ON) {
+                                    this.hopper.setTeleportTrigger(TeleportTrigger.DISABLED);
                                 }
-                                plugin.getDataManager().updateHopper(hopper);
+                                this.plugin.getDataManager().updateHopper(this.hopper);
                                 constructGUI();
                             }
                         });
                 canTeleport = false;
             } else if (canFilter) {
                 setButton("filter", slot, filter, (event) -> {
-                    hopper.setActivePlayer(player);
-                    guiManager.showGUI(player, new GUIFilter(plugin, hopper, player));
+                    this.hopper.setActivePlayer(this.player);
+                    this.guiManager.showGUI(this.player, new GUIFilter(this.plugin, this.hopper, this.player));
                 });
                 canFilter = false;
             } else {
-                if (modules.isEmpty()) break;
+                if (modules.isEmpty()) {
+                    break;
+                }
                 Module module = modules.get(0);
                 modules.remove(module);
-                setButton(module.getName().toLowerCase().replace(" ", "_"), slot, module.getGUIButton(hopper),
-                        (event) -> module.runButtonPress(player, hopper, event.clickType));
+                setButton(module.getName().toLowerCase().replace(" ", "_"), slot, module.getGUIButton(this.hopper),
+                        (event) -> module.runButtonPress(this.player, this.hopper, event.clickType));
             }
         }
 
         if (Settings.HOPPER_UPGRADING.getBoolean()) {
             if (Settings.UPGRADE_WITH_XP.getBoolean()
                     && level.getCostExperience() != -1
-                    && player.hasPermission("EpicHoppers.Upgrade.XP")) {
+                    && this.player.hasPermission("EpicHoppers.Upgrade.XP")) {
                 setButton("upgrade_xp", 1, 2, GuiUtils.createButtonItem(
-                        Settings.XP_ICON.getMaterial(CompatibleMaterial.EXPERIENCE_BOTTLE),
-                        plugin.getLocale().getMessage("interface.hopper.upgradewithxp").getMessage(),
-                        nextLevel != null
-                                ? plugin.getLocale().getMessage("interface.hopper.upgradewithxplore")
-                                .processPlaceholder("cost", nextLevel.getCostExperience()).getMessage()
-                                : plugin.getLocale().getMessage("interface.hopper.alreadymaxed").getMessage()),
+                                Settings.XP_ICON.getMaterial(CompatibleMaterial.EXPERIENCE_BOTTLE),
+                                this.plugin.getLocale().getMessage("interface.hopper.upgradewithxp").getMessage(),
+                                nextLevel != null
+                                        ? this.plugin.getLocale().getMessage("interface.hopper.upgradewithxplore")
+                                        .processPlaceholder("cost", nextLevel.getCostExperience()).getMessage()
+                                        : this.plugin.getLocale().getMessage("interface.hopper.alreadymaxed").getMessage()),
                         (event) -> {
-                            hopper.upgrade(player, CostType.EXPERIENCE);
-                            hopper.overview(guiManager, player);
+                            this.hopper.upgrade(this.player, CostType.EXPERIENCE);
+                            this.hopper.overview(this.guiManager, this.player);
                         });
             }
             if (Settings.UPGRADE_WITH_ECONOMY.getBoolean()
                     && level.getCostEconomy() != -1
-                    && player.hasPermission("EpicHoppers.Upgrade.ECO")) {
+                    && this.player.hasPermission("EpicHoppers.Upgrade.ECO")) {
                 setButton("upgrade_economy", 1, 6, GuiUtils.createButtonItem(
-                        Settings.ECO_ICON.getMaterial(CompatibleMaterial.SUNFLOWER),
-                        plugin.getLocale().getMessage("interface.hopper.upgradewitheconomy").getMessage(),
-                        nextLevel != null
-                                ? plugin.getLocale().getMessage("interface.hopper.upgradewitheconomylore")
-                                .processPlaceholder("cost", Methods.formatEconomy(nextLevel.getCostEconomy())).getMessage()
-                                : plugin.getLocale().getMessage("interface.hopper.alreadymaxed").getMessage()),
+                                Settings.ECO_ICON.getMaterial(CompatibleMaterial.SUNFLOWER),
+                                this.plugin.getLocale().getMessage("interface.hopper.upgradewitheconomy").getMessage(),
+                                nextLevel != null
+                                        ? this.plugin.getLocale().getMessage("interface.hopper.upgradewitheconomylore")
+                                        .processPlaceholder("cost", NumberUtils.formatNumber(nextLevel.getCostEconomy())).getMessage()
+                                        : this.plugin.getLocale().getMessage("interface.hopper.alreadymaxed").getMessage()),
                         (event) -> {
-                            hopper.upgrade(player, CostType.ECONOMY);
-                            hopper.overview(guiManager, player);
+                            this.hopper.upgrade(this.player, CostType.ECONOMY);
+                            this.hopper.overview(this.guiManager, this.player);
                         });
             }
         }
 
         setItem("hopper", 13, item);
 
-        hopper.setLastPlayerOpened(player.getUniqueId());
+        this.hopper.setLastPlayerOpened(this.player.getUniqueId());
     }
 
     private void runTask() {
-        task = Bukkit.getScheduler().scheduleSyncRepeatingTask(plugin, () -> {
-            if (!inventory.getViewers().isEmpty())
+        this.task = Bukkit.getScheduler().scheduleSyncRepeatingTask(this.plugin, () -> {
+            if (!this.inventory.getViewers().isEmpty()) {
                 this.constructGUI();
+            }
         }, 5L, 5L);
     }
 }

src/main/java/com/songoda/epichoppers/gui/GUISmeltable.java

@@ -17,14 +17,15 @@ import java.util.List;
 import java.util.stream.Collectors;
 
 public class GUISmeltable extends CustomizableGui {
-
     private final EpicHoppers plugin;
     private final Hopper hopper;
-    private int maxPages;
-    private ModuleAutoSmelter moduleAutoSmelter;
+    private final int maxPages;
+    private final ModuleAutoSmelter moduleAutoSmelter;
 
-    private static List<CompatibleMaterial> burnables = Arrays.stream(CompatibleMaterial.values())
-            .filter(m -> m.getBurnResult() != null).collect(Collectors.toList());
+    private static final List<CompatibleMaterial> BURNABLES = Arrays
+            .stream(CompatibleMaterial.values())
+            .filter(material -> material.getBurnResult() != null)
+            .collect(Collectors.toList());
 
     public GUISmeltable(ModuleAutoSmelter moduleAutoSmelter, EpicHoppers plugin, Hopper hopper) {
         super(plugin, "smeltable");
@@ -32,9 +33,9 @@ public class GUISmeltable extends CustomizableGui {
         this.hopper = hopper;
         this.moduleAutoSmelter = moduleAutoSmelter;
 
-        int smeltables = burnables.size();
+        int smeltables = BURNABLES.size();
 
-        maxPages = (int) Math.ceil(smeltables / 32.);
+        this.maxPages = (int) Math.ceil(smeltables / 32.);
 
         setTitle(Methods.formatName(hopper.getLevel().getLevel()) + TextUtils.formatText(" &7-&f Smelting"));
         setRows(6);
@@ -57,44 +58,44 @@ public class GUISmeltable extends CustomizableGui {
         mirrorFill("mirrorfill_3", 0, 2, true, true, glass3);
         mirrorFill("mirrorfill_4", 1, 0, true, true, glass2);
 
-        int smeltableIndex = page == 1 ? 0 : 32 * (page - 1);
+        int smeltableIndex = this.page == 1 ? 0 : 32 * (this.page - 1);
 
         for (int i = 9; i < 45; i++) {
             if (i == 9 || i == 17 || i == 44 || i == 36) continue;
             setItem(i, null);
             clearActions(i);
-            if (smeltableIndex >= (burnables.size() - 1)) continue;
-            CompatibleMaterial burnable = burnables.get(smeltableIndex);
-            setButton(i, getItemStack(burnable, moduleAutoSmelter.isSmeltable(hopper, burnable)), (event) -> {
-                moduleAutoSmelter.toggleSmeltable(hopper, burnable);
-                setItem(event.slot, getItemStack(burnable, moduleAutoSmelter.isSmeltable(hopper, burnable)));
+            if (smeltableIndex >= (BURNABLES.size() - 1)) continue;
+            CompatibleMaterial burnable = BURNABLES.get(smeltableIndex);
+            setButton(i, getItemStack(burnable, this.moduleAutoSmelter.isSmeltable(this.hopper, burnable)), (event) -> {
+                this.moduleAutoSmelter.toggleSmeltable(this.hopper, burnable);
+                setItem(event.slot, getItemStack(burnable, this.moduleAutoSmelter.isSmeltable(this.hopper, burnable)));
             });
             smeltableIndex++;
         }
 
         clearActions(51);
-        if (page < maxPages) {
+        if (this.page < this.maxPages) {
             setButton("next", 51, GuiUtils.createButtonItem(CompatibleMaterial.ARROW,
-                    plugin.getLocale().getMessage("general.nametag.next").getMessage()),
+                            this.plugin.getLocale().getMessage("general.nametag.next").getMessage()),
                     (event) -> {
-                        page++;
+                        this.page++;
                         showPage();
                     });
         }
 
         clearActions(47);
-        if (page > 1) {
+        if (this.page > 1) {
             setButton("back", 47, GuiUtils.createButtonItem(CompatibleMaterial.ARROW,
-                    plugin.getLocale().getMessage("general.nametag.back").getMessage()),
+                            this.plugin.getLocale().getMessage("general.nametag.back").getMessage()),
                     (event) -> {
-                        page--;
+                        this.page--;
                         showPage();
                     });
         }
 
         setButton("exit", 49, GuiUtils.createButtonItem(CompatibleMaterial.OAK_DOOR,
-                plugin.getLocale().getMessage("general.nametag.exit").getMessage()),
-                (event) -> hopper.overview(plugin.getGuiManager(), event.player));
+                        this.plugin.getLocale().getMessage("general.nametag.exit").getMessage()),
+                (event) -> this.hopper.overview(this.plugin.getGuiManager(), event.player));
     }
 
     public ItemStack getItemStack(CompatibleMaterial material, boolean enabled) {
@@ -104,7 +105,7 @@ public class GUISmeltable extends CustomizableGui {
         meta.setLore(Arrays.asList(TextUtils.formatText("   &7-> &e" + material.getBurnResult().name()),
                 TextUtils.formatText("&7Enabled: &6" + String.valueOf(enabled).toLowerCase() + "&7."),
                 "",
-                plugin.getLocale().getMessage("interface.hopper.toggle").getMessage()));
+                this.plugin.getLocale().getMessage("interface.hopper.toggle").getMessage()));
         item.setItemMeta(meta);
 
         return item;

src/main/java/com/songoda/epichoppers/hopper/Filter.java

@@ -8,7 +8,6 @@ import java.util.Collections;
 import java.util.List;
 
 public class Filter {
-
     private List<ItemStack> whiteList = new ArrayList<>();
     private List<ItemStack> blackList = new ArrayList<>();
     private List<ItemStack> voidList = new ArrayList<>();
@@ -21,7 +20,7 @@ public class Filter {
 
 
     public List<ItemStack> getWhiteList() {
-        return whiteList != null ? whiteList : Collections.emptyList();
+        return this.whiteList != null ? this.whiteList : Collections.emptyList();
     }
 
 
@@ -31,7 +30,7 @@ public class Filter {
 
 
     public List<ItemStack> getBlackList() {
-        return blackList != null ? blackList : Collections.emptyList();
+        return this.blackList != null ? this.blackList : Collections.emptyList();
     }
 
 
@@ -41,7 +40,7 @@ public class Filter {
 
 
     public List<ItemStack> getVoidList() {
-        return voidList != null ? voidList : Collections.emptyList();
+        return this.voidList != null ? this.voidList : Collections.emptyList();
     }
 
 
@@ -51,7 +50,7 @@ public class Filter {
 
 
     public List<ItemStack> getAutoSellWhiteList() {
-        return autoSellWhiteList != null ? autoSellWhiteList : Collections.emptyList();
+        return this.autoSellWhiteList != null ? this.autoSellWhiteList : Collections.emptyList();
     }
 
 
@@ -61,7 +60,7 @@ public class Filter {
 
 
     public List<ItemStack> getAutoSellBlackList() {
-        return autoSellBlackList != null ? autoSellBlackList : Collections.emptyList();
+        return this.autoSellBlackList != null ? this.autoSellBlackList : Collections.emptyList();
     }
 
 
@@ -71,7 +70,7 @@ public class Filter {
 
 
     public Location getEndPoint() {
-        return endPoint;
+        return this.endPoint;
     }
 
 
@@ -82,19 +81,23 @@ public class Filter {
     public void addItem(ItemStack item, ItemType type) {
         switch (type) {
             case WHITELIST:
-                whiteList.add(item);
+                this.whiteList.add(item);
                 break;
+
             case BLACKLIST:
-                blackList.add(item);
+                this.blackList.add(item);
                 break;
+
             case VOID:
-                voidList.add(item);
+                this.voidList.add(item);
                 break;
+
             case AUTO_SELL_WHITELIST:
-                autoSellWhiteList.add(item);
+                this.autoSellWhiteList.add(item);
                 break;
+
             case AUTO_SELL_BLACKLIST:
-                autoSellBlackList.add(item);
+                this.autoSellBlackList.add(item);
                 break;
         }
     }

src/main/java/com/songoda/epichoppers/hopper/Hopper.java

@@ -14,7 +14,11 @@ import com.songoda.epichoppers.player.PlayerData;
 import com.songoda.epichoppers.settings.Settings;
 import com.songoda.epichoppers.utils.CostType;
 import com.songoda.epichoppers.utils.Methods;
-import org.bukkit.*;
+import org.bukkit.Bukkit;
+import org.bukkit.GameMode;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.World;
 import org.bukkit.block.Block;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.Inventory;
@@ -27,16 +31,12 @@ import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 
-/**
- * Created by songoda on 3/14/2017.
- */
 public class Hopper {
-
     // Id for database use.
     private int id;
 
     private final Location location;
-    private Level level = EpicHoppers.getInstance().getLevelManager().getLowestLevel();
+    private Level level = EpicHoppers.getPlugin(EpicHoppers.class).getLevelManager().getLowestLevel();
     private UUID lastPlayerOpened = null;
     private UUID placedBy = null;
     private final List<Location> linkedBlocks = new ArrayList<>();
@@ -55,10 +55,10 @@ public class Hopper {
     }
 
     public void overview(GuiManager guiManager, Player player) {
-        if (lastPlayerOpened != null
-                && lastPlayerOpened != player.getUniqueId()
-                && Bukkit.getPlayer(lastPlayerOpened) != null) {
-            Bukkit.getPlayer(lastPlayerOpened).closeInventory();
+        if (this.lastPlayerOpened != null &&
+                this.lastPlayerOpened != player.getUniqueId() &&
+                Bukkit.getPlayer(this.lastPlayerOpened) != null) {
+            Bukkit.getPlayer(this.lastPlayerOpened).closeInventory();
         }
 
         HopperAccessEvent accessEvent = new HopperAccessEvent(player, this);
@@ -67,36 +67,43 @@ public class Hopper {
             return;
         }
 
-        if (placedBy == null) placedBy = player.getUniqueId();
+        if (this.placedBy == null) {
+            this.placedBy = player.getUniqueId();
+        }
 
-        EpicHoppers instance = EpicHoppers.getInstance();
-        if (!player.hasPermission("epichoppers.overview")) return;
+        EpicHoppers instance = EpicHoppers.getPlugin(EpicHoppers.class);
+        if (!player.hasPermission("epichoppers.overview")) {
+            return;
+        }
 
         setActivePlayer(player);
         guiManager.showGUI(player, new GUIOverview(instance, this, player));
     }
 
     public void forceClose() {
-        if (activePlayer != null)
-            activePlayer.closeInventory();
+        if (this.activePlayer != null) {
+            this.activePlayer.closeInventory();
+        }
     }
 
     public void dropItems() {
-        Inventory inventory = ((InventoryHolder) location.getBlock().getState()).getInventory();
-        World world = location.getWorld();
+        Inventory inventory = ((InventoryHolder) this.location.getBlock().getState()).getInventory();
+        World world = this.location.getWorld();
 
         for (ItemStack itemStack : inventory.getContents()) {
             if (itemStack == null || itemStack.getType() == Material.AIR) {
                 continue;
             }
 
-            world.dropItemNaturally(location, itemStack);
+            world.dropItemNaturally(this.location, itemStack);
         }
     }
 
     public void upgrade(Player player, CostType type) {
-        EpicHoppers plugin = EpicHoppers.getInstance();
-        if (!plugin.getLevelManager().getLevels().containsKey(this.level.getLevel() + 1)) return;
+        EpicHoppers plugin = EpicHoppers.getPlugin(EpicHoppers.class);
+        if (!plugin.getLevelManager().getLevels().containsKey(this.level.getLevel() + 1)) {
+            return;
+        }
 
         Level level = plugin.getLevelManager().getLevel(this.level.getLevel() + 1);
         int cost = type == CostType.ECONOMY ? level.getCostEconomy() : level.getCostExperience();
@@ -125,7 +132,7 @@ public class Hopper {
     }
 
     private void upgradeFinal(Level level, Player player) {
-        EpicHoppers plugin = EpicHoppers.getInstance();
+        EpicHoppers plugin = EpicHoppers.getPlugin(EpicHoppers.class);
         this.level = level;
         plugin.getDataManager().updateHopper(this);
         syncName();
@@ -136,7 +143,7 @@ public class Hopper {
             plugin.getLocale().getMessage("event.upgrade.maxed")
                     .processPlaceholder("level", level.getLevel()).sendPrefixedMessage(player);
         }
-        Location loc = location.clone().add(.5, .5, .5);
+        Location loc = this.location.clone().add(.5, .5, .5);
 
         if (!Settings.UPGRADE_PARTICLE_TYPE.getString().trim().isEmpty()) {
             CompatibleParticleHandler.spawnParticles(
@@ -155,35 +162,36 @@ public class Hopper {
     }
 
     private void syncName() {
-        org.bukkit.block.Hopper hopper = (org.bukkit.block.Hopper) location.getBlock().getState();
-        if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_10))
-            hopper.setCustomName(Methods.formatName(level.getLevel()));
+        org.bukkit.block.Hopper hopper = (org.bukkit.block.Hopper) this.location.getBlock().getState();
+        if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_10)) {
+            hopper.setCustomName(Methods.formatName(this.level.getLevel()));
+        }
         hopper.update(true);
     }
 
     public void timeout(Player player) {
-        EpicHoppers instance = EpicHoppers.getInstance();
-        syncId = Bukkit.getScheduler().scheduleSyncDelayedTask(instance, () -> {
+        EpicHoppers instance = EpicHoppers.getPlugin(EpicHoppers.class);
+        this.syncId = Bukkit.getScheduler().scheduleSyncDelayedTask(instance, () -> {
             PlayerData playerData = instance.getPlayerDataManager().getPlayerData(player);
             if (playerData.getSyncType() != null && playerData.getLastHopper() == this) {
                 instance.getLocale().getMessage("event.hopper.synctimeout").sendPrefixedMessage(player);
                 playerData.setSyncType(null);
             }
-        }, Settings.LINK_TIMEOUT.getLong() * level.getLinkAmount());
+        }, Settings.LINK_TIMEOUT.getLong() * this.level.getLinkAmount());
     }
 
     public void link(Block toLink, boolean filtered, Player player) {
-        EpicHoppers instance = EpicHoppers.getInstance();
+        EpicHoppers instance = EpicHoppers.getPlugin(EpicHoppers.class);
 
-        if (location.getWorld().equals(toLink.getLocation().getWorld())
+        if (this.location.getWorld().equals(toLink.getLocation().getWorld())
                 && !player.hasPermission("EpicHoppers.Override")
                 && !player.hasPermission("EpicHoppers.Admin")
-                && location.distance(toLink.getLocation()) > level.getRange()) {
+                && this.location.distance(toLink.getLocation()) > this.level.getRange()) {
             instance.getLocale().getMessage("event.hopper.syncoutofrange").sendPrefixedMessage(player);
             return;
         }
 
-        if (linkedBlocks.contains(toLink.getLocation())) {
+        if (this.linkedBlocks.contains(toLink.getLocation())) {
             instance.getLocale().getMessage("event.hopper.already").sendPrefixedMessage(player);
             return;
         }
@@ -200,14 +208,14 @@ public class Hopper {
         }
         this.lastPlayerOpened = player.getUniqueId();
 
-        if (level.getLinkAmount() > 1) {
-            if (linkedBlocks.size() >= level.getLinkAmount()) {
+        if (this.level.getLinkAmount() > 1) {
+            if (this.linkedBlocks.size() >= this.level.getLinkAmount()) {
                 instance.getLocale().getMessage("event.hopper.syncdone").sendPrefixedMessage(player);
                 cancelSync(player);
                 return;
             }
             instance.getLocale().getMessage("event.hopper.syncsuccessmore")
-                    .processPlaceholder("amount", level.getLinkAmount() - linkedBlocks.size())
+                    .processPlaceholder("amount", this.level.getLinkAmount() - this.linkedBlocks.size())
                     .sendPrefixedMessage(player);
             return;
         }
@@ -236,31 +244,31 @@ public class Hopper {
     }
 
     public Location getLocation() {
-        return location.clone();
+        return this.location.clone();
     }
 
     public Block getBlock() {
-        return location.getBlock();
+        return this.location.getBlock();
     }
 
     public World getWorld() {
-        return location.getWorld();
+        return this.location.getWorld();
     }
 
     public int getX() {
-        return location.getBlockX();
+        return this.location.getBlockX();
     }
 
     public int getY() {
-        return location.getBlockY();
+        return this.location.getBlockY();
     }
 
     public int getZ() {
-        return location.getBlockZ();
+        return this.location.getBlockZ();
     }
 
     public Level getLevel() {
-        return level;
+        return this.level;
     }
 
     public void setLevel(Level level) {
@@ -268,7 +276,7 @@ public class Hopper {
     }
 
     public UUID getPlacedBy() {
-        return placedBy;
+        return this.placedBy;
     }
 
     public void setPlacedBy(UUID placedBy) {
@@ -276,15 +284,15 @@ public class Hopper {
     }
 
     public UUID getLastPlayerOpened() {
-        return lastPlayerOpened;
+        return this.lastPlayerOpened;
     }
 
     public void setLastPlayerOpened(UUID uuid) {
-        lastPlayerOpened = uuid;
+        this.lastPlayerOpened = uuid;
     }
 
     public TeleportTrigger getTeleportTrigger() {
-        return teleportTrigger;
+        return this.teleportTrigger;
     }
 
     public void setTeleportTrigger(TeleportTrigger teleportTrigger) {
@@ -292,14 +300,15 @@ public class Hopper {
     }
 
     public List<Location> getLinkedBlocks() {
-        return new ArrayList<>(linkedBlocks);
+        return new ArrayList<>(this.linkedBlocks);
     }
 
     public void addLinkedBlock(Location location, LinkType type) {
-        if (type == LinkType.REGULAR)
-            linkedBlocks.add(location);
-        else
-            filter.setEndPoint(location);
+        if (type == LinkType.REGULAR) {
+            this.linkedBlocks.add(location);
+        } else {
+            this.filter.setEndPoint(location);
+        }
     }
 
     public void removeLinkedBlock(Location location) {
@@ -311,7 +320,7 @@ public class Hopper {
     }
 
     public Filter getFilter() {
-        return filter;
+        return this.filter;
     }
 
     public void setFilter(Filter filter) {
@@ -339,12 +348,12 @@ public class Hopper {
     }
 
     public void cancelSync(Player player) {
-        Bukkit.getScheduler().cancelTask(syncId);
-        EpicHoppers.getInstance().getPlayerDataManager().getPlayerData(player).setSyncType(null);
+        Bukkit.getScheduler().cancelTask(this.syncId);
+        EpicHoppers.getPlugin(EpicHoppers.class).getPlayerDataManager().getPlayerData(player).setSyncType(null);
     }
 
     public int getId() {
-        return id;
+        return this.id;
     }
 
     public void setId(int id) {
@@ -352,7 +361,7 @@ public class Hopper {
     }
 
     public Player getActivePlayer() {
-        return activePlayer;
+        return this.activePlayer;
     }
 
     public void setActivePlayer(Player activePlayer) {

src/main/java/com/songoda/epichoppers/hopper/HopperBuilder.java

@@ -9,7 +9,6 @@ import org.bukkit.block.Block;
 import java.util.UUID;
 
 public class HopperBuilder {
-
     private final Hopper hopper;
 
     public HopperBuilder(Location location) {
@@ -31,8 +30,9 @@ public class HopperBuilder {
     }
 
     public HopperBuilder addLinkedBlocks(LinkType type, Location... linkedBlocks) {
-        for (Location location : linkedBlocks)
-            hopper.addLinkedBlock(location, type);
+        for (Location location : linkedBlocks) {
+            this.hopper.addLinkedBlock(location, type);
+        }
         return this;
     }
 

src/main/java/com/songoda/epichoppers/hopper/HopperManager.java

@@ -13,9 +13,14 @@ import java.util.HashMap;
 import java.util.Map;
 
 public class HopperManager {
+    private final Map<Location, Hopper> registeredHoppers = new HashMap<>();
+    private final EpicHoppers plugin;
+
     protected boolean ready;
 
-    private final Map<Location, Hopper> registeredHoppers = new HashMap<>();
+    public HopperManager(EpicHoppers plugin) {
+        this.plugin = plugin;
+    }
 
     /**
      * Sets {@link #isReady()} to {@code true}.<br>
@@ -33,18 +38,19 @@ public class HopperManager {
     }
 
     public Hopper addHopper(Hopper hopper) {
-        registeredHoppers.put(roundLocation(hopper.getLocation()), hopper);
+        this.registeredHoppers.put(roundLocation(hopper.getLocation()), hopper);
         return hopper;
     }
 
     @Deprecated
     public void addHopper(Location location, Hopper hopper) {
-        registeredHoppers.put(roundLocation(location), hopper);
+        this.registeredHoppers.put(roundLocation(location), hopper);
     }
 
     public void addHoppers(Collection<Hopper> hoppers) {
-        for (Hopper hopper : hoppers)
-            registeredHoppers.put(hopper.getLocation(), hopper);
+        for (Hopper hopper : hoppers) {
+            this.registeredHoppers.put(hopper.getLocation(), hopper);
+        }
     }
 
     /**
@@ -56,26 +62,29 @@ public class HopperManager {
     public Hopper removeHopper(Location location) {
         Hopper removed = this.registeredHoppers.remove(location);
 
-        for (Hopper hopper : this.registeredHoppers.values())
+        for (Hopper hopper : this.registeredHoppers.values()) {
             hopper.removeLinkedBlock(location);
+        }
 
-        for (Level level : EpicHoppers.getInstance().getLevelManager().getLevels().values())
-            for (Module module : level.getRegisteredModules())
+        for (Level level : this.plugin.getLevelManager().getLevels().values()) {
+            for (Module module : level.getRegisteredModules()) {
                 module.clearData(removed);
+            }
+        }
 
         return removed;
     }
 
     public Hopper getHopper(Location location) {
-        if (!registeredHoppers.containsKey(location = roundLocation(location))) {
+        if (!this.registeredHoppers.containsKey(location = roundLocation(location))) {
             if (!this.ready) {
                 throw new IllegalStateException("Hoppers are still being loaded");
             }
 
             Hopper hopper = addHopper(new Hopper(location));
-            EpicHoppers.getInstance().getDataManager().createHopper(hopper);
+            this.plugin.getDataManager().createHopper(hopper);
         }
-        return registeredHoppers.get(location);
+        return this.registeredHoppers.get(location);
     }
 
     public Hopper getHopper(Block block) {
@@ -86,11 +95,11 @@ public class HopperManager {
      * <em>Returns {@code false} if {@link #isReady()} is false too</em>
      */
     public boolean isHopper(Location location) {
-        return registeredHoppers.containsKey(roundLocation(location));
+        return this.registeredHoppers.containsKey(roundLocation(location));
     }
 
     public Map<Location, Hopper> getHoppers() {
-        return Collections.unmodifiableMap(registeredHoppers);
+        return Collections.unmodifiableMap(this.registeredHoppers);
     }
 
     public Hopper getHopperFromPlayer(Player player) {
@@ -98,7 +107,7 @@ public class HopperManager {
             throw new IllegalStateException("Hoppers are still being loaded");
         }
 
-        for (Hopper hopper : registeredHoppers.values()) {
+        for (Hopper hopper : this.registeredHoppers.values()) {
             if (hopper.getLastPlayerOpened() == player.getUniqueId()) {
                 return hopper;
             }

src/main/java/com/songoda/epichoppers/hopper/ItemType.java

@@ -1,7 +1,5 @@
 package com.songoda.epichoppers.hopper;
 
 public enum ItemType {
-
     WHITELIST, BLACKLIST, VOID, AUTO_SELL_WHITELIST, AUTO_SELL_BLACKLIST
-
 }

src/main/java/com/songoda/epichoppers/hopper/LinkType.java

@@ -1,6 +1,5 @@
 package com.songoda.epichoppers.hopper;
 
 public enum LinkType {
-
     REGULAR, REJECT
 }

src/main/java/com/songoda/epichoppers/hopper/levels/Level.java

@@ -7,7 +7,6 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class Level {
-
     private final ArrayList<Module> registeredModules;
     private final List<String> description = new ArrayList<>();
     private final int level, costExperience, costEconomy, range, amount, linkAmount;
@@ -29,91 +28,108 @@ public class Level {
     }
 
     public void buildDescription() {
-        EpicHoppers instance = EpicHoppers.getInstance();
+        EpicHoppers instance = EpicHoppers.getPlugin(EpicHoppers.class);
 
-        description.clear();
+        this.description.clear();
 
-        description.add(instance.getLocale().getMessage("interface.hopper.range")
-                .processPlaceholder("range", range).getMessage());
-        description.add(instance.getLocale().getMessage("interface.hopper.amount")
-                .processPlaceholder("amount", amount).getMessage());
-        if (linkAmount != 1)
-            description.add(instance.getLocale().getMessage("interface.hopper.linkamount")
-                    .processPlaceholder("amount", linkAmount).getMessage());
-        if (filter)
-            description.add(instance.getLocale().getMessage("interface.hopper.filter")
-                    .processPlaceholder("enabled", EpicHoppers.getInstance().getLocale()
+        this.description.add(instance.getLocale().getMessage("interface.hopper.range")
+                .processPlaceholder("range", this.range).getMessage());
+        this.description.add(instance.getLocale().getMessage("interface.hopper.amount")
+                .processPlaceholder("amount", this.amount).getMessage());
+        if (this.linkAmount != 1) {
+            this.description.add(instance.getLocale().getMessage("interface.hopper.linkamount")
+                    .processPlaceholder("amount", this.linkAmount).getMessage());
+        }
+        if (this.filter) {
+            this.description.add(instance.getLocale().getMessage("interface.hopper.filter")
+                    .processPlaceholder("enabled", instance.getLocale()
                             .getMessage("general.word.enabled").getMessage()).getMessage());
-        if (teleport)
-            description.add(instance.getLocale().getMessage("interface.hopper.teleport")
-                    .processPlaceholder("enabled", EpicHoppers.getInstance()
-                            .getLocale().getMessage("general.word.enabled").getMessage()).getMessage());
+        }
+        if (this.teleport) {
+            this.description.add(instance
+                    .getLocale()
+                    .getMessage("interface.hopper.teleport")
+                    .processPlaceholder(
+                            "enabled",
+                            instance
+                                    .getLocale()
+                                    .getMessage("general.word.enabled")
+                                    .getMessage())
+                    .getMessage());
+        }
 
-        for (Module module : registeredModules) {
-            description.add(module.getDescription());
+        for (Module module : this.registeredModules) {
+            this.description.add(module.getDescription());
         }
     }
 
 
     public int getLevel() {
-        return level;
+        return this.level;
     }
 
 
     public int getRange() {
-        return range;
+        return this.range;
     }
 
 
     public int getAmount() {
-        return amount;
+        return this.amount;
     }
 
 
     public boolean isFilter() {
-        return filter;
+        return this.filter;
     }
 
 
     public boolean isTeleport() {
-        return teleport;
+        return this.teleport;
     }
 
 
     public int getLinkAmount() {
-        return linkAmount;
+        return this.linkAmount;
     }
 
 
     public int getCostExperience() {
-        return costExperience;
+        return this.costExperience;
     }
 
 
     public int getCostEconomy() {
-        return costEconomy;
+        return this.costEconomy;
     }
 
 
     public List<String> getDescription() {
-        return new ArrayList<>(description);
+        return new ArrayList<>(this.description);
     }
 
 
     public ArrayList<Module> getRegisteredModules() {
-        return new ArrayList<>(registeredModules);
+        return new ArrayList<>(this.registeredModules);
     }
 
 
     public void addModule(Module module) {
-        registeredModules.add(module);
+        this.registeredModules.add(module);
         buildDescription();
     }
 
 
     public Module getModule(String name) {
-        return registeredModules == null ? null :
-                registeredModules.stream().filter(module -> module.getName().equals(name)).findFirst().orElse(null);
+        if (this.registeredModules == null) {
+            return null;
+        }
+
+        for (Module module : this.registeredModules) {
+            if (module.getName().equals(name)) {
+                return module;
+            }
+        }
+        return null;
     }
 }
-

src/main/java/com/songoda/epichoppers/hopper/levels/LevelManager.java

@@ -14,24 +14,22 @@ import java.util.NavigableMap;
 import java.util.TreeMap;
 
 public class LevelManager {
-
     private final NavigableMap<Integer, Level> registeredLevels = new TreeMap<>();
 
-
     public void addLevel(int level, int costExperience, int costEconomy, int range, int amount, boolean filter, boolean teleport, int linkAmount, ArrayList<Module> modules) {
-        registeredLevels.put(level, new Level(level, costExperience, costEconomy, range, amount, filter, teleport, linkAmount, modules));
+        this.registeredLevels.put(level, new Level(level, costExperience, costEconomy, range, amount, filter, teleport, linkAmount, modules));
     }
 
-
     public Level getLevel(int level) {
-        return registeredLevels.get(level);
+        return this.registeredLevels.get(level);
     }
 
     public Level getLevel(ItemStack item) {
         NBTItem nbtItem = new NBTItem(item);
 
-        if (nbtItem.hasKey("level"))
+        if (nbtItem.hasTag("level")) {
             return getLevel(nbtItem.getInteger("level"));
+        }
 
         // Legacy trash.
         if (item.hasItemMeta() && item.getItemMeta().getDisplayName().contains(":")) {
@@ -45,8 +43,9 @@ public class LevelManager {
     public boolean isEpicHopper(ItemStack item) {
         NBTCore nbt = NmsManager.getNbt();
 
-        if (nbt.of(item).has("level"))
+        if (nbt.of(item).has("level")) {
             return true;
+        }
 
         return item.hasItemMeta()
                 // Legacy Trash.
@@ -55,25 +54,25 @@ public class LevelManager {
 
 
     public Level getLowestLevel() {
-        return registeredLevels.firstEntry().getValue();
+        return this.registeredLevels.firstEntry().getValue();
     }
 
 
     public Level getHighestLevel() {
-        return registeredLevels.lastEntry().getValue();
+        return this.registeredLevels.lastEntry().getValue();
     }
 
 
     public boolean isLevel(int level) {
-        return registeredLevels.containsKey(level);
+        return this.registeredLevels.containsKey(level);
     }
 
 
     public Map<Integer, Level> getLevels() {
-        return Collections.unmodifiableMap(registeredLevels);
+        return Collections.unmodifiableMap(this.registeredLevels);
     }
 
     public void clear() {
-        registeredLevels.clear();
+        this.registeredLevels.clear();
     }
 }

src/main/java/com/songoda/epichoppers/hopper/levels/modules/Module.java

@@ -16,21 +16,20 @@ import java.util.List;
 import java.util.Map;
 
 public abstract class Module {
-
-    private static final Map<String, Config> configs = new HashMap<>();
+    private static final Map<String, Config> CONFIGS = new HashMap<>();
 
     protected final EpicHoppers plugin;
     private final Config config;
 
     public Module(EpicHoppers plugin) {
         this.plugin = plugin;
-        if (!configs.containsKey(getName())) {
+        if (!CONFIGS.containsKey(getName())) {
             Config config = new Config(plugin, File.separator + "modules", getName() + ".yml");
-            configs.put(getName(), config);
+            CONFIGS.put(getName(), config);
             config.load();
 
         }
-        this.config = configs.get(getName());
+        this.config = CONFIGS.get(getName());
     }
 
     public abstract String getName();
@@ -50,7 +49,7 @@ public abstract class Module {
     }
 
     public void saveData(Hopper hopper, String setting, Object value, Object toCache) {
-        config.set("data." + Methods.serializeLocation(hopper.getLocation()) + "." + setting, value);
+        this.config.set("data." + Methods.serializeLocation(hopper.getLocation()) + "." + setting, value);
         modifyDataCache(hopper, setting, toCache);
     }
 
@@ -60,20 +59,21 @@ public abstract class Module {
 
     protected Object getData(Hopper hopper, String setting) {
         String cacheStr = getName() + "." + setting;
-        if (hopper.isDataCachedInModuleCache(cacheStr))
+        if (hopper.isDataCachedInModuleCache(cacheStr)) {
             return hopper.getDataFromModuleCache(cacheStr);
+        }
 
-        Object data = config.get("data." + Methods.serializeLocation(hopper.getLocation()) + "." + setting);
+        Object data = this.config.get("data." + Methods.serializeLocation(hopper.getLocation()) + "." + setting);
         modifyDataCache(hopper, setting, data);
         return data;
     }
 
     public void clearData(Hopper hopper) {
-        config.set("data." + Methods.serializeLocation(hopper.getLocation()), null);
+        this.config.set("data." + Methods.serializeLocation(hopper.getLocation()), null);
         hopper.clearModuleCache();
     }
 
     public void saveDataToFile() {
-        config.save();
+        this.config.save();
     }
 }

src/main/java/com/songoda/epichoppers/hopper/levels/modules/ModuleAutoCrafting.java

@@ -31,15 +31,15 @@ import java.util.Objects;
 import java.util.concurrent.ConcurrentHashMap;
 
 public class ModuleAutoCrafting extends Module {
+    private static final Map<ItemStack, Recipes> CACHED_RECIPES = new ConcurrentHashMap<>();
+    private static final Map<Hopper, ItemStack> CACHED_CRAFTING = new ConcurrentHashMap<>();
+    private static final ItemStack NO_CRAFT = new ItemStack(Material.AIR);
 
-    private static final Map<ItemStack, Recipes> cachedRecipes = new ConcurrentHashMap<>();
-    private static final Map<Hopper, ItemStack> cachedCrafting = new ConcurrentHashMap<>();
-    private static final ItemStack noCraft = new ItemStack(Material.AIR);
-    private boolean crafterEjection;
+    private final boolean crafterEjection;
 
     public ModuleAutoCrafting(EpicHoppers plugin) {
         super(plugin);
-        crafterEjection = Settings.AUTOCRAFT_JAM_EJECT.getBoolean();
+        this.crafterEjection = Settings.AUTOCRAFT_JAM_EJECT.getBoolean();
     }
 
     @Override
@@ -50,8 +50,9 @@ public class ModuleAutoCrafting extends Module {
     @Override
     public void run(Hopper hopper, StorageContainerCache.Cache hopperCache) {
         final ItemStack toCraft;
-        if (hopper == null || (toCraft = getAutoCrafting(hopper)) == null || toCraft.getType() == Material.AIR)
+        if (hopper == null || (toCraft = getAutoCrafting(hopper)) == null || toCraft.getType() == Material.AIR) {
             return;
+        }
 
         synchronized (hopperCache) {    //TODO: Check if this is required
             ItemStack[] items = hopperCache.cachedInventory;
@@ -67,8 +68,12 @@ public class ModuleAutoCrafting extends Module {
                     for (int i = 0; i < items.length; i++) {
                         ItemStack item = items[i];
 
-                        if (item == null) continue;
-                        if (item.hasItemMeta() && item.getItemMeta().hasDisplayName()) continue;
+                        if (item == null) {
+                            continue;
+                        }
+                        if (item.hasItemMeta() && item.getItemMeta().hasDisplayName()) {
+                            continue;
+                        }
 
                         boolean sameMaterial = Methods.isSimilarMaterial(item, ingredient.item);
 
@@ -82,7 +87,9 @@ public class ModuleAutoCrafting extends Module {
                             }
 
                             // Still doesn't not match --> Skip this item
-                            if (!sameMaterial) continue;
+                            if (!sameMaterial) {
+                                continue;
+                            }
                         }
 
                         if (item.getAmount() >= amount) {
@@ -95,7 +102,9 @@ public class ModuleAutoCrafting extends Module {
                     }
 
                     // Not enough ingredients for this recipe
-                    if (amount != 0) continue recipeLoop;
+                    if (amount != 0) {
+                        continue recipeLoop;
+                    }
                 }
 
                 boolean freeSlotAfterRemovingIngredients =
@@ -105,7 +114,7 @@ public class ModuleAutoCrafting extends Module {
                                                 recipe.result.isSimilar(item)));
 
                 // jam check: is this hopper gummed up?
-                if (crafterEjection && !freeSlotAfterRemovingIngredients) {
+                if (this.crafterEjection && !freeSlotAfterRemovingIngredients) {
                     // Crafter can't function if there's nowhere to put the output
                     // ¯\_(ツ)_/¯
 
@@ -180,10 +189,10 @@ public class ModuleAutoCrafting extends Module {
     public ItemStack getGUIButton(Hopper hopper) {
         ItemStack crafting = CompatibleMaterial.CRAFTING_TABLE.getItem();
         ItemMeta craftingmeta = crafting.getItemMeta();
-        craftingmeta.setDisplayName(EpicHoppers.getInstance().getLocale().getMessage("interface.hopper.craftingtitle")
+        craftingmeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.craftingtitle")
                 .getMessage());
         ArrayList<String> lorecrafting = new ArrayList<>();
-        String[] parts = EpicHoppers.getInstance().getLocale().getMessage("interface.hopper.craftinglore")
+        String[] parts = this.plugin.getLocale().getMessage("interface.hopper.craftinglore")
                 .getMessage().split("\\|");
         for (String line : parts) {
             lorecrafting.add(TextUtils.formatText(line));
@@ -196,7 +205,7 @@ public class ModuleAutoCrafting extends Module {
     @Override
     public void runButtonPress(Player player, Hopper hopper, ClickType type) {
         hopper.setActivePlayer(player);
-        EpicHoppers.getInstance().getGuiManager().showGUI(player, new GUICrafting(this, hopper, player));
+        this.plugin.getGuiManager().showGUI(player, new GUICrafting(this,this.plugin, hopper, player));
     }
 
     @Override
@@ -205,26 +214,30 @@ public class ModuleAutoCrafting extends Module {
         if (itemStack != null && itemStack.getType() != Material.AIR) {
             return getRecipes(itemStack).getPossibleIngredientTypes();
         }
-        return Collections.EMPTY_LIST;
+        return Collections.emptyList();
     }
 
     @Override
     public String getDescription() {
-        return EpicHoppers.getInstance().getLocale().getMessage("interface.hopper.crafting").processPlaceholder("enabled",
-                EpicHoppers.getInstance().getLocale().getMessage("general.word.enabled").getMessage()).getMessage();
+        return this.plugin.getLocale()
+                .getMessage("interface.hopper.crafting")
+                .processPlaceholder("enabled", this.plugin.getLocale().getMessage("general.word.enabled").getMessage())
+                .getMessage();
     }
 
     @Override
     public void clearData(Hopper hopper) {
         super.clearData(hopper);
-        cachedCrafting.remove(hopper);
+        CACHED_CRAFTING.remove(hopper);
     }
 
     private Recipes getRecipes(ItemStack toCraft) {
-        Recipes recipes = cachedRecipes.get(toCraft);
+        Recipes recipes = CACHED_RECIPES.get(toCraft);
         if (Settings.AUTOCRAFT_BLACKLIST.getStringList().stream()
-                .anyMatch(r -> r.equalsIgnoreCase(toCraft.getType().name())))
+                .anyMatch(r -> r.equalsIgnoreCase(toCraft.getType().name()))) {
             return new Recipes();
+        }
+
         if (recipes == null) {
             try {
                 recipes = new Recipes(Bukkit.getServer().getRecipesFor(toCraft));
@@ -238,32 +251,37 @@ public class ModuleAutoCrafting extends Module {
                         Recipe recipe = recipeIterator.next();
 
                         ItemStack stack = recipe.getResult();
-                        if (Methods.isSimilarMaterial(stack, toCraft))
+                        if (Methods.isSimilarMaterial(stack, toCraft)) {
                             recipes.addRecipe(recipe);
+                        }
                     } catch (Throwable ignored) {
                     }
                 }
             }
 
-            cachedRecipes.put(toCraft, recipes);
+            CACHED_RECIPES.put(toCraft, recipes);
         }
+
         return recipes;
     }
 
     public ItemStack getAutoCrafting(Hopper hopper) {
-        if (cachedCrafting.containsKey(hopper))
-            return cachedCrafting.get(hopper);
+        if (CACHED_CRAFTING.containsKey(hopper)) {
+            return CACHED_CRAFTING.get(hopper);
+        }
 
         Object autocrafting = getData(hopper, "autocrafting");
         ItemStack toCraft = autocrafting instanceof ItemStack ? (ItemStack) autocrafting : decode((String) autocrafting);
-        cachedCrafting.put(hopper, toCraft == null ? noCraft : toCraft);
+        CACHED_CRAFTING.put(hopper, toCraft == null ? NO_CRAFT : toCraft);
         return toCraft;
     }
 
     public void setAutoCrafting(Hopper hopper, Player player, ItemStack autoCrafting) {
         saveData(hopper, "autocrafting", autoCrafting == null ? null : encode(autoCrafting), autoCrafting);
-        cachedCrafting.put(hopper, autoCrafting == null ? noCraft : autoCrafting);
-        if (autoCrafting == null) return;
+        CACHED_CRAFTING.put(hopper, autoCrafting == null ? NO_CRAFT : autoCrafting);
+        if (autoCrafting == null) {
+            return;
+        }
         int excess = autoCrafting.getAmount() - 1;
         autoCrafting.setAmount(1);
         if (excess > 0 && player != null) {
@@ -285,7 +303,7 @@ public class ModuleAutoCrafting extends Module {
                 1, Short.parseShort(autoCraftingParts.length == 2 ? autoCraftingParts[1] : "0"));
     }
 
-    private final static class Recipes {
+    private static final class Recipes {
         private final List<SimpleRecipe> recipes = new ArrayList<>();
         // Used for the blacklist to ensure that items are not going to get transferred
         private final List<Material> possibleIngredientTypes = new ArrayList<>();
@@ -298,11 +316,11 @@ public class ModuleAutoCrafting extends Module {
         }
 
         public List<SimpleRecipe> getRecipes() {
-            return Collections.unmodifiableList(recipes);
+            return Collections.unmodifiableList(this.recipes);
         }
 
         public List<Material> getPossibleIngredientTypes() {
-            return Collections.unmodifiableList(possibleIngredientTypes);
+            return Collections.unmodifiableList(this.possibleIngredientTypes);
         }
 
         public void addRecipe(Recipe recipe) {
@@ -315,19 +333,21 @@ public class ModuleAutoCrafting extends Module {
             }
 
             // Skip unsupported recipe type
-            if (simpleRecipe == null) return;
+            if (simpleRecipe == null) {
+                return;
+            }
 
             this.recipes.add(simpleRecipe);
 
             // Keep a list of all possible ingredients.
             for (SimpleRecipe.SimpleIngredient ingredient : simpleRecipe.ingredients) {
-                if (!possibleIngredientTypes.contains(ingredient.item.getType())) {
-                    possibleIngredientTypes.add(ingredient.item.getType());
+                if (!this.possibleIngredientTypes.contains(ingredient.item.getType())) {
+                    this.possibleIngredientTypes.add(ingredient.item.getType());
                 }
 
                 for (ItemStack material : ingredient.alternativeTypes) {
-                    if (!possibleIngredientTypes.contains(material.getType())) {
-                        possibleIngredientTypes.add(material.getType());
+                    if (!this.possibleIngredientTypes.contains(material.getType())) {
+                        this.possibleIngredientTypes.add(material.getType());
                     }
                 }
             }
@@ -338,15 +358,15 @@ public class ModuleAutoCrafting extends Module {
         }
 
         public boolean hasRecipes() {
-            return !recipes.isEmpty();
+            return !this.recipes.isEmpty();
         }
 
         public void clearRecipes() {
-            recipes.clear();
+            this.recipes.clear();
         }
     }
 
-    private final static class SimpleRecipe {
+    private static final class SimpleRecipe {
         private final SimpleIngredient[] ingredients;
         private final ItemStack result;
 
@@ -384,7 +404,9 @@ public class ModuleAutoCrafting extends Module {
                 } catch (NoSuchMethodError ignore) {    // Method missing in Spigot 1.12.2
                 }
 
-                if (item == null) continue;
+                if (item == null) {
+                    continue;
+                }
 
                 processIngredient(ingredients, item, rChoice);
             }
@@ -449,26 +471,29 @@ public class ModuleAutoCrafting extends Module {
             }
 
             public int getAdditionalAmount() {
-                return additionalAmount;
+                return this.additionalAmount;
             }
 
             public void addAdditionalAmount(int amountToAdd) {
-                additionalAmount += amountToAdd;
+                this.additionalAmount += amountToAdd;
             }
 
             /**
              * Like {@link #equals(Object)} but ignores {@link #additionalAmount} and {@link ItemStack#getAmount()}
              *
              * @return If two {@link SimpleIngredient} objects are equal
-             *         while ignoring any item amounts, true otherwise false
+             * while ignoring any item amounts, true otherwise false
              */
             public boolean isSimilar(Object o) {
-                if (this == o) return true;
-                if (o == null || getClass() != o.getClass()) return false;
+                if (this == o) {
+                    return true;
+                }
+                if (o == null || getClass() != o.getClass()) {
+                    return false;
+                }
 
                 SimpleIngredient that = (SimpleIngredient) o;
-                return item.isSimilar(that.item) &&
-                        Arrays.equals(alternativeTypes, that.alternativeTypes);
+                return this.item.isSimilar(that.item) && Arrays.equals(this.alternativeTypes, that.alternativeTypes);
             }
         }
     }

src/main/java/com/songoda/epichoppers/hopper/levels/modules/ModuleAutoSell.java

@@ -2,6 +2,7 @@ package com.songoda.epichoppers.hopper.levels.modules;
 
 import com.songoda.core.compatibility.CompatibleMaterial;
 import com.songoda.core.hooks.EconomyManager;
+import com.songoda.core.utils.NumberUtils;
 import com.songoda.core.utils.TextUtils;
 import com.songoda.epichoppers.EpicHoppers;
 import com.songoda.epichoppers.gui.GUIAutoSellFilter;
@@ -25,13 +26,14 @@ import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
 public class ModuleAutoSell extends Module {
+    private static final Map<Hopper, Boolean> CACHED_NOTIFICATIONS = new ConcurrentHashMap<>();
 
     private final int timeOut;
     private final int hopperTickRate;
-    private static final Map<Hopper, Boolean> cachedNotifications = new ConcurrentHashMap<>();
 
     public ModuleAutoSell(EpicHoppers plugin, int timeOut) {
         super(plugin);
+
         this.timeOut = timeOut * 20;
         this.hopperTickRate = Settings.HOP_TICKS.getInt();
     }
@@ -46,15 +48,19 @@ public class ModuleAutoSell extends Module {
 
         int currentTime = getTime(hopper);
 
-        if (currentTime == -9999) return;
+        if (currentTime == -9999) {
+            return;
+        }
 
-        int subtract = getTime(hopper) - hopperTickRate;
+        int subtract = getTime(hopper) - this.hopperTickRate;
 
         if (subtract <= 0) {
             int amountSold = 0;
             double totalValue = 0;
 
-            if (!EconomyManager.isEnabled()) return;
+            if (!EconomyManager.isEnabled()) {
+                return;
+            }
 
             OfflinePlayer player = Bukkit.getOfflinePlayer(hopper.getPlacedBy());
 
@@ -62,18 +68,22 @@ public class ModuleAutoSell extends Module {
             for (int i = 0; i < hopperCache.cachedInventory.length; i++) {
                 final ItemStack itemStack = hopperCache.cachedInventory[i];
 
-                if (itemStack == null) continue;
+                if (itemStack == null) {
+                    continue;
+                }
 
                 Filter filter = hopper.getFilter();
 
                 if (filter.getAutoSellWhiteList().isEmpty()) {
                     // Check blacklist
-                    if (filter.getAutoSellBlackList().stream().anyMatch(item -> Methods.isSimilarMaterial(itemStack, item)))
+                    if (filter.getAutoSellBlackList().stream().anyMatch(item -> Methods.isSimilarMaterial(itemStack, item))) {
                         continue;
+                    }
                 } else {
                     // Check whitelist
-                    if (filter.getAutoSellWhiteList().stream().noneMatch(item -> Methods.isSimilarMaterial(itemStack, item)))
+                    if (filter.getAutoSellWhiteList().stream().noneMatch(item -> Methods.isSimilarMaterial(itemStack, item))) {
                         continue;
+                    }
                 }
 
                 // Get the value from config or ShopGuiPlus or EconomyShopGui
@@ -103,7 +113,9 @@ public class ModuleAutoSell extends Module {
                             .map(s -> Double.valueOf(s.split(",")[1])).orElse(0.0);
                 }
 
-                if (value <= 0) continue;
+                if (value <= 0) {
+                    continue;
+                }
 
                 double sellingFor = value * itemStack.getAmount();
 
@@ -112,15 +124,16 @@ public class ModuleAutoSell extends Module {
                 hopperCache.removeItem(i);
             }
 
-            if (totalValue != 0)
+            if (totalValue != 0) {
                 EconomyManager.deposit(player, totalValue);
+            }
             if (totalValue != 0 && player.isOnline() && isNotifying(hopper)) {
-                plugin.getLocale().getMessage("event.hopper.autosell")
+                this.plugin.getLocale().getMessage("event.hopper.autosell")
                         .processPlaceholder("items", amountSold)
-                        .processPlaceholder("amount", Methods.formatEconomy(totalValue)).sendPrefixedMessage(player.getPlayer());
+                        .processPlaceholder("amount", NumberUtils.formatNumber(totalValue)).sendPrefixedMessage(player.getPlayer());
             }
 
-            modifyDataCache(hopper, "time", timeOut);
+            modifyDataCache(hopper, "time", this.timeOut);
             return;
         }
 
@@ -132,15 +145,18 @@ public class ModuleAutoSell extends Module {
         ItemStack sellItem = CompatibleMaterial.SUNFLOWER.getItem();
         ItemMeta sellMeta = sellItem.getItemMeta();
 
-        sellMeta.setDisplayName(EpicHoppers.getInstance().getLocale().getMessage("interface.hopper.selltitle").getMessage());
+        sellMeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.selltitle").getMessage());
         ArrayList<String> loreSell = new ArrayList<>();
 
-        String[] parts = EpicHoppers.getInstance().getLocale().getMessage("interface.hopper.selllore")
-                .processPlaceholder("timeleft", getTime(hopper) == -9999 ? "\u221E" : (int) Math.floor(getTime(hopper) / 20))
-                .processPlaceholder("state", isNotifying(hopper)).getMessage().split("\\|");
+        String[] parts = this.plugin.getLocale().getMessage("interface.hopper.selllore")
+                .processPlaceholder("timeleft", getTime(hopper) == -9999 ? "∞" : (int) Math.floor(getTime(hopper) / 20))
+                .processPlaceholder("state", isNotifying(hopper))
+                .getMessage()
+                .split("\\|");
 
-        for (String line : parts)
+        for (String line : parts) {
             loreSell.add(TextUtils.formatText(line));
+        }
 
         sellMeta.setLore(loreSell);
         sellItem.setItemMeta(sellMeta);
@@ -151,7 +167,7 @@ public class ModuleAutoSell extends Module {
     public void runButtonPress(Player player, Hopper hopper, ClickType type) {
         if (type == ClickType.LEFT) {
             if (getTime(hopper) == -9999) {
-                saveData(hopper, "time", timeOut);
+                saveData(hopper, "time", this.timeOut);
             } else {
                 saveData(hopper, "time", -9999);
             }
@@ -160,7 +176,7 @@ public class ModuleAutoSell extends Module {
         } else if (type == ClickType.SHIFT_LEFT || type == ClickType.SHIFT_RIGHT) {
             // Any shift click opens AutoSell filter configuration GUI
             hopper.setActivePlayer(player);
-            EpicHoppers.getInstance().getGuiManager().showGUI(player, new GUIAutoSellFilter(EpicHoppers.getInstance(), hopper));
+            this.plugin.getGuiManager().showGUI(player, new GUIAutoSellFilter(this.plugin, hopper));
         }
     }
 
@@ -171,33 +187,37 @@ public class ModuleAutoSell extends Module {
 
     @Override
     public String getDescription() {
-        return EpicHoppers.getInstance().getLocale().getMessage("interface.hopper.autosell")
-                .processPlaceholder("seconds", (int) Math.floor(timeOut / 20)).getMessage();
+        return this.plugin.getLocale()
+                .getMessage("interface.hopper.autosell")
+                .processPlaceholder("seconds", (int) Math.floor(this.timeOut / 20))
+                .getMessage();
     }
 
     @Override
     public void clearData(Hopper hopper) {
         super.clearData(hopper);
-        cachedNotifications.remove(hopper);
+        CACHED_NOTIFICATIONS.remove(hopper);
     }
 
     private boolean isNotifying(Hopper hopper) {
-        Boolean enabled = cachedNotifications.get(hopper);
+        Boolean enabled = CACHED_NOTIFICATIONS.get(hopper);
         if (enabled == null) {
             Object notifications = getData(hopper, "notifications");
-            cachedNotifications.put(hopper, enabled = notifications != null && (boolean) notifications);
+            CACHED_NOTIFICATIONS.put(hopper, enabled = notifications != null && (boolean) notifications);
         }
         return enabled;
     }
 
     public void setNotifying(Hopper hopper, boolean enable) {
         saveData(hopper, "notifications", enable);
-        cachedNotifications.put(hopper, enable);
+        CACHED_NOTIFICATIONS.put(hopper, enable);
     }
 
     private int getTime(Hopper hopper) {
         Object time = getData(hopper, "time");
-        if (time == null) return -9999;
+        if (time == null) {
+            return -9999;
+        }
         return (int) time;
     }
 }

src/main/java/com/songoda/epichoppers/hopper/levels/modules/ModuleAutoSmelter.java

@@ -18,7 +18,6 @@ import java.util.Collections;
 import java.util.List;
 
 public class ModuleAutoSmelter extends Module {
-
     private final int timeOut;
     private final int hopperTickRate;
 
@@ -35,21 +34,28 @@ public class ModuleAutoSmelter extends Module {
 
     @Override
     public void run(Hopper hopper, StorageContainerCache.Cache hopperCache) {
-        if (!isEnabled(hopper)) return;
+        if (!isEnabled(hopper)) {
+            return;
+        }
 
         int currentTime = getTime(hopper);
+        if (currentTime == -9999) {
+            return;
+        }
 
-        if (currentTime == -9999) return;
-
-        int subtract = currentTime - hopperTickRate;
+        int subtract = currentTime - this.hopperTickRate;
 
 
         if (subtract <= 0) {
             for (int i = 0; i < 5; i++) {
                 final ItemStack itemStack = hopperCache.cachedInventory[i];
-                if (itemStack == null) continue;
+                if (itemStack == null) {
+                    continue;
+                }
                 CompatibleMaterial material = CompatibleMaterial.getMaterial(itemStack);
-                if (!isSmeltable(hopper, material)) continue;
+                if (!isSmeltable(hopper, material)) {
+                    continue;
+                }
                 CompatibleMaterial result = CompatibleMaterial.getMaterial(itemStack).getBurnResult();
 
                 if (hopperCache.addItem(result.getItem())) {
@@ -63,7 +69,7 @@ public class ModuleAutoSmelter extends Module {
                 }
             }
 
-            modifyDataCache(hopper, "time", timeOut);
+            modifyDataCache(hopper, "time", this.timeOut);
             return;
         }
 
@@ -74,16 +80,20 @@ public class ModuleAutoSmelter extends Module {
     public ItemStack getGUIButton(Hopper hopper) {
         ItemStack block = CompatibleMaterial.IRON_INGOT.getItem();
         ItemMeta blockmeta = block.getItemMeta();
-        blockmeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.smelttitle").getMessage());
-        ArrayList<String> loreblock = new ArrayList<>();
-        String[] parts = plugin.getLocale().getMessage("interface.hopper.smeltlore").processPlaceholder("timeleft",
-                getTime(hopper) == -9999 ? "\u221E" : (int) Math.floor(getTime(hopper) / 20.0)).processPlaceholder("enabled",
-                isEnabled(hopper) ? EpicHoppers.getInstance().getLocale().getMessage("general.word.enabled").getMessage()
-                        : EpicHoppers.getInstance().getLocale().getMessage("general.word.disabled").getMessage()).getMessage().split("\\|");
+        blockmeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.smelttitle").getMessage());
+        ArrayList<String> loreBlock = new ArrayList<>();
+        String[] parts = this.plugin.getLocale().getMessage("interface.hopper.smeltlore")
+                .processPlaceholder("timeleft", getTime(hopper) == -9999 ? "∞" : (int) Math.floor(getTime(hopper) / 20.0))
+                .processPlaceholder("enabled", isEnabled(hopper) ?
+                        this.plugin.getLocale().getMessage("general.word.enabled").getMessage() :
+                        this.plugin.getLocale().getMessage("general.word.disabled").getMessage()
+                )
+                .getMessage()
+                .split("\\|");
         for (String line : parts) {
-            loreblock.add(TextUtils.formatText(line));
+            loreBlock.add(TextUtils.formatText(line));
         }
-        blockmeta.setLore(loreblock);
+        blockmeta.setLore(loreBlock);
         block.setItemMeta(blockmeta);
         return block;
     }
@@ -91,57 +101,68 @@ public class ModuleAutoSmelter extends Module {
     public void runButtonPress(Player player, Hopper hopper, ClickType type) {
         if (type == ClickType.LEFT) {
             hopper.setActivePlayer(player);
-            EpicHoppers.getInstance().getGuiManager().showGUI(player, new GUISmeltable(this, plugin, hopper));
-        } else if (type == ClickType.RIGHT)
+            this.plugin.getGuiManager().showGUI(player, new GUISmeltable(this, this.plugin, hopper));
+        } else if (type == ClickType.RIGHT) {
             toggleEnabled(hopper);
+        }
     }
 
     @Override
     public List<Material> getBlockedItems(Hopper hopper) {
-        if (getTime(hopper) == -9999)
+        if (getTime(hopper) == -9999) {
             return Collections.emptyList();
+        }
 
         List<Material> blockedItems = new ArrayList<>();
-        for (CompatibleMaterial material : CompatibleMaterial.values())
-            if (material.getBurnResult() != null && isSmeltable(hopper, material))
+        for (CompatibleMaterial material : CompatibleMaterial.values()) {
+            if (material.getBurnResult() != null && isSmeltable(hopper, material)) {
                 blockedItems.add(material.getMaterial());
+            }
+        }
 
         return blockedItems;
     }
 
     @Override
     public String getDescription() {
-        return plugin.getLocale().getMessage("interface.hopper.autosmelt")
-                .processPlaceholder("ticks", (int) Math.floor(timeOut / 20.0)).getMessage();
+        return this.plugin.getLocale().getMessage("interface.hopper.autosmelt")
+                .processPlaceholder("ticks", (int) Math.floor(this.timeOut / 20.0)).getMessage();
     }
 
     private int getTime(Hopper hopper) {
         Object time = getData(hopper, "time");
-        if (time == null) return -9999;
+        if (time == null) {
+            return -9999;
+        }
         return (int) time;
     }
 
     private boolean isEnabled(Hopper hopper) {
         Object obj = getData(hopper, "time");
-        if (obj == null) return false;
+        if (obj == null) {
+            return false;
+        }
         return ((int) obj) != -9999;
     }
 
     public boolean isSmeltable(Hopper hopper, CompatibleMaterial material) {
         Object obj = getData(hopper, material.name());
-        if (obj == null) return false;
+        if (obj == null) {
+            return false;
+        }
 
         return ((boolean) obj);
     }
 
     private void toggleEnabled(Hopper hopper) {
-        if (isEnabled(hopper))
+        if (isEnabled(hopper)) {
             saveData(hopper, "time", -9999);
-        else
-            saveData(hopper, "time", timeOut);
+        } else {
+            saveData(hopper, "time", this.timeOut);
+        }
     }
 
     public void toggleSmeltable(Hopper hopper, CompatibleMaterial material) {
         saveData(hopper, material.name(), !isSmeltable(hopper, material));
     }
-}
+}

src/main/java/com/songoda/epichoppers/hopper/levels/modules/ModuleBlockBreak.java

@@ -25,10 +25,10 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Stream;
 
 public class ModuleBlockBreak extends Module {
+    private static final Map<Hopper, Boolean> CACHED_BLOCKS = new ConcurrentHashMap<>();
 
     private final int ticksPerBreak;
     private final Map<Hopper, Integer> blockTick = new HashMap<>();
-    private static final Map<Hopper, Boolean> cachedBlocks = new ConcurrentHashMap<>();
 
     public ModuleBlockBreak(EpicHoppers plugin, int amount) {
         super(plugin);
@@ -42,47 +42,51 @@ public class ModuleBlockBreak extends Module {
 
     @Override
     public void run(Hopper hopper, StorageContainerCache.Cache hopperCache) {
-
-        if (!isEnabled(hopper))
+        if (!isEnabled(hopper)) {
             return;
+        }
 
         // don't try to break stuff if we can't grab stuff
         // (for simplicity, just assume that no empty slots mean there's a good chance we won't be able to pick something new up)
-        if (Stream.of(hopperCache.cachedInventory)
-                .allMatch(item -> item != null && item.getAmount() > 0))
+        if (Stream.of(hopperCache.cachedInventory).allMatch(item -> item != null && item.getAmount() > 0)) {
             return;
+        }
 
-        Integer tick = blockTick.get(hopper);
+        Integer tick = this.blockTick.get(hopper);
         if (tick == null) {
-            blockTick.put(hopper, 1);
+            this.blockTick.put(hopper, 1);
             return;
-        } else if (tick < ticksPerBreak) {
-            blockTick.put(hopper, tick + 1);
+        } else if (tick < this.ticksPerBreak) {
+            this.blockTick.put(hopper, tick + 1);
             return;
         } else {
-            blockTick.put(hopper, 0);
+            this.blockTick.put(hopper, 0);
         }
 
         Block above = hopper.getLocation().getBlock().getRelative(0, 1, 0);
 
         // Don't break farm items from custom containers
-        if (plugin.getContainerManager().getCustomContainer(above) != null)
+        if (this.plugin.getContainerManager().getCustomContainer(above) != null) {
             return;
+        }
 
         // don't break blacklisted blocks, fluids, or containers
         if (Settings.BLOCKBREAK_BLACKLIST.getStringList().contains(above.getType().name())
                 || above.getType() == Material.WATER
                 || above.getType() == Material.LAVA
-                || above.getType() == Material.AIR)
+                || above.getType() == Material.AIR) {
             return;
+        }
 
         if (Settings.ALLOW_BLOCKBREAK_CONTAINERS.getBoolean()
-                && above.getState() instanceof InventoryHolder)
+                && above.getState() instanceof InventoryHolder) {
             return;
+        }
 
         // Let's break the block!
-        if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_9))
+        if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_9)) {
             above.getWorld().playSound(above.getLocation(), Sound.BLOCK_STONE_BREAK, 1F, 1F);
+        }
         Location locationAbove = above.getLocation();
         locationAbove.add(.5, .5, .5);
 
@@ -106,35 +110,36 @@ public class ModuleBlockBreak extends Module {
             }
         }
 
-        boolean waterlogged = false;
-        if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13)
+        boolean waterlogged = ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13)
                 && above.getBlockData() instanceof org.bukkit.block.data.Waterlogged
-                && ((org.bukkit.block.data.Waterlogged) above.getBlockData()).isWaterlogged()) {
-            waterlogged = true;
-        }
+                && ((org.bukkit.block.data.Waterlogged) above.getBlockData()).isWaterlogged();
 
         above.breakNaturally(new ItemStack(Material.DIAMOND_PICKAXE));
 
-        if (waterlogged)
+        if (waterlogged) {
             above.setType(Material.WATER);
+        }
     }
 
     @Override
     public ItemStack getGUIButton(Hopper hopper) {
         ItemStack block = new ItemStack(Material.IRON_ORE, 1);
-        ItemMeta blockmeta = block.getItemMeta();
-        blockmeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.blocktitle").getMessage());
-        ArrayList<String> loreblock = new ArrayList<>();
-        String[] parts = plugin.getLocale().getMessage("interface.hopper.blocklore")
+        ItemMeta blockMeta = block.getItemMeta();
+        blockMeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.blocktitle").getMessage());
+        ArrayList<String> loreBlock = new ArrayList<>();
+        String[] parts = this.plugin.getLocale()
+                .getMessage("interface.hopper.blocklore")
                 .processPlaceholder("enabled", isEnabled(hopper)
-                        ? plugin.getLocale().getMessage("general.word.enabled").getMessage()
-                        : plugin.getLocale().getMessage("general.word.disabled").getMessage())
-                .getMessage().split("\\|");
+                        ? this.plugin.getLocale().getMessage("general.word.enabled").getMessage()
+                        : this.plugin.getLocale().getMessage("general.word.disabled").getMessage()
+                )
+                .getMessage()
+                .split("\\|");
         for (String line : parts) {
-            loreblock.add(TextUtils.formatText(line));
+            loreBlock.add(TextUtils.formatText(line));
         }
-        blockmeta.setLore(loreblock);
-        block.setItemMeta(blockmeta);
+        blockMeta.setLore(loreBlock);
+        block.setItemMeta(blockMeta);
         return block;
     }
 
@@ -150,26 +155,26 @@ public class ModuleBlockBreak extends Module {
 
     @Override
     public String getDescription() {
-        return plugin.getLocale().getMessage("interface.hopper.blockbreak")
-                .processPlaceholder("ticks", ticksPerBreak).getMessage();
+        return this.plugin.getLocale().getMessage("interface.hopper.blockbreak")
+                .processPlaceholder("ticks", this.ticksPerBreak).getMessage();
     }
 
     @Override
     public void clearData(Hopper hopper) {
         super.clearData(hopper);
-        cachedBlocks.remove(hopper);
+        CACHED_BLOCKS.remove(hopper);
     }
 
     public void setEnabled(Hopper hopper, boolean enable) {
         saveData(hopper, "blockbreak", enable);
-        cachedBlocks.put(hopper, enable);
+        CACHED_BLOCKS.put(hopper, enable);
     }
 
     public boolean isEnabled(Hopper hopper) {
-        Boolean enabled = cachedBlocks.get(hopper);
+        Boolean enabled = CACHED_BLOCKS.get(hopper);
         if (enabled == null) {
             Object isBlockBreaking = getData(hopper, "blockbreak");
-            cachedBlocks.put(hopper, enabled = isBlockBreaking != null && (boolean) isBlockBreaking);
+            CACHED_BLOCKS.put(hopper, enabled = isBlockBreaking != null && (boolean) isBlockBreaking);
         }
         return enabled;
     }

src/main/java/com/songoda/epichoppers/hopper/levels/modules/ModuleMobHopper.java

@@ -20,7 +20,6 @@ import java.util.List;
 import java.util.Map;
 
 public class ModuleMobHopper extends Module {
-
     private final int amount;
     private final Map<Block, Integer> blockTick = new HashMap<>();
 
@@ -39,41 +38,45 @@ public class ModuleMobHopper extends Module {
     public void run(Hopper hopper, StorageContainerCache.Cache hopperCache) {
         Block block = hopper.getLocation().getBlock();
 
-        if (!blockTick.containsKey(block)) {
-            blockTick.put(block, 1);
+        if (!this.blockTick.containsKey(block)) {
+            this.blockTick.put(block, 1);
             return;
         }
-        int tick = blockTick.get(block);
+        int tick = this.blockTick.get(block);
         int put = tick + 1;
-        blockTick.put(block, put);
-        if (tick < amount || !isEnabled(hopper)) return;
+        this.blockTick.put(block, put);
+        if (tick < this.amount || !isEnabled(hopper)) {
+            return;
+        }
 
         hopper.getWorld().getNearbyEntities(hopper.getLocation(), 5, 5, 5).stream()
                 .filter(entity -> entity instanceof LivingEntity && !(entity instanceof Player) &&
                         !(entity instanceof ArmorStand)).limit(1).forEach(entity -> {
-            Location location = hopper.getLocation().add(.5, 1, .5);
-            if (location.getBlock().getType() != Material.AIR) return;
+                    Location location = hopper.getLocation().add(.5, 1, .5);
+                    if (location.getBlock().getType() != Material.AIR) {
+                        return;
+                    }
 
-            entity.teleport(location);
-            ((LivingEntity) entity).damage(99999999);
-        });
-        blockTick.remove(block);
+                    entity.teleport(location);
+                    ((LivingEntity) entity).damage(99999999);
+                });
+        this.blockTick.remove(block);
     }
 
     @Override
     public ItemStack getGUIButton(Hopper hopper) {
         ItemStack block = new ItemStack(Material.ROTTEN_FLESH, 1);
-        ItemMeta blockmeta = block.getItemMeta();
-        blockmeta.setDisplayName(plugin.getLocale().getMessage("interface.hopper.mobtitle").getMessage());
-        ArrayList<String> loreblock = new ArrayList<>();
-        String[] parts = plugin.getLocale().getMessage("interface.hopper.moblore").processPlaceholder("enabled",
-                isEnabled(hopper) ? EpicHoppers.getInstance().getLocale().getMessage("general.word.enabled").getMessage()
-                        : EpicHoppers.getInstance().getLocale().getMessage("general.word.disabled").getMessage()).getMessage().split("\\|");
+        ItemMeta blockMeta = block.getItemMeta();
+        blockMeta.setDisplayName(this.plugin.getLocale().getMessage("interface.hopper.mobtitle").getMessage());
+        ArrayList<String> loreBlock = new ArrayList<>();
+        String[] parts = this.plugin.getLocale().getMessage("interface.hopper.moblore").processPlaceholder("enabled",
+                isEnabled(hopper) ? this.plugin.getLocale().getMessage("general.word.enabled").getMessage()
+                        : this.plugin.getLocale().getMessage("general.word.disabled").getMessage()).getMessage().split("\\|");
         for (String line : parts) {
-            loreblock.add(TextUtils.formatText(line));
+            loreBlock.add(TextUtils.formatText(line));
         }
-        blockmeta.setLore(loreblock);
-        block.setItemMeta(blockmeta);
+        blockMeta.setLore(loreBlock);
+        block.setItemMeta(blockMeta);
         return block;
     }
 
@@ -89,12 +92,14 @@ public class ModuleMobHopper extends Module {
 
     @Override
     public String getDescription() {
-        return plugin.getLocale().getMessage("interface.hopper.mobhopper")
-                .processPlaceholder("ticks", amount).getMessage();
+        return this.plugin.getLocale()
+                .getMessage("interface.hopper.mobhopper")
+                .processPlaceholder("ticks", this.amount)
+                .getMessage();
     }
 
     public boolean isEnabled(Hopper hopper) {
         Object isMobHopper = getData(hopper, "mobhopper");
         return isMobHopper != null && (boolean) isMobHopper;
     }
-}
+}

src/main/java/com/songoda/epichoppers/hopper/levels/modules/ModuleSuction.java

@@ -31,14 +31,13 @@ import java.util.UUID;
 import java.util.stream.Collectors;
 
 public class ModuleSuction extends Module {
+    private static final List<UUID> BLACKLIST = new ArrayList<>();
+
+    private static final boolean WILD_STACKER = Bukkit.getPluginManager().isPluginEnabled("WildStacker");
+    private static final boolean ULTIMATE_STACKER = Bukkit.getPluginManager().isPluginEnabled("UltimateStacker");
 
     private final int maxSearchRadius;
 
-    private static List<UUID> blacklist = new ArrayList<>();
-
-    private static final boolean wildStacker = Bukkit.getPluginManager().isPluginEnabled("WildStacker");
-    private static final boolean ultimateStacker = Bukkit.getPluginManager().isPluginEnabled("UltimateStacker");
-
     public ModuleSuction(EpicHoppers plugin, int amount) {
         super(plugin);
         this.maxSearchRadius = amount;
@@ -53,7 +52,9 @@ public class ModuleSuction extends Module {
     public void run(Hopper hopper, StorageContainerCache.Cache hopperCache) {
         double radius = getRadius(hopper) + .5;
 
-        if (!isEnabled(hopper)) return;
+        if (!isEnabled(hopper)) {
+            return;
+        }
 
         Set<Item> itemsToSuck = hopper.getLocation().getWorld().getNearbyEntities(hopper.getLocation().add(0.5, 0.5, 0.5), radius, radius, radius)
                 .stream()
@@ -64,8 +65,9 @@ public class ModuleSuction extends Module {
                 .map(Item.class::cast)
                 .collect(Collectors.toSet());
 
-        if (itemsToSuck.isEmpty())
+        if (itemsToSuck.isEmpty()) {
             return;
+        }
 
         boolean filterEndpoint = hopper.getFilter().getEndPoint() != null;
 
@@ -76,7 +78,6 @@ public class ModuleSuction extends Module {
         }
 
         for (Item item : itemsToSuck) {
-
             ItemStack itemStack = item.getItemStack();
 
             if (item.getPickupDelay() == 0) {
@@ -84,21 +85,23 @@ public class ModuleSuction extends Module {
                 continue;
             }
 
-            if (itemStack.getType().name().contains("SHULKER_BOX"))
+            if (itemStack.getType().name().contains("SHULKER_BOX")) {
                 return;
+            }
 
             if (itemStack.hasItemMeta() && itemStack.getItemMeta().hasDisplayName() &&
                     itemStack.getItemMeta().getDisplayName().startsWith("***")) {
                 return; //Compatibility with Shop instance: https://www.spigotmc.org/resources/shop-a-simple-intuitive-shop-instance.9628/
             }
 
-            if (blacklist.contains(item.getUniqueId()))
+            if (BLACKLIST.contains(item.getUniqueId())) {
                 return;
+            }
 
             // respect filter if no endpoint
             if (!filterEndpoint
                     && !(hopper.getFilter().getWhiteList().isEmpty() && hopper.getFilter().getBlackList().isEmpty())) {
-                // this hopper has a filter with no rejection endpoint, so don't absorb disalowed items
+                // this hopper has a filter with no rejection endpoint, so don't absorb disallowed items
                 // whitelist has priority
                 if (!hopper.getFilter().getWhiteList().isEmpty()) {
                     // is this item on the whitelist?
@@ -117,28 +120,30 @@ public class ModuleSuction extends Module {
 
             if (Settings.EMIT_INVENTORYPICKUPITEMEVENT.getBoolean()) {
                 hopperInventory.setContents(hopperCache.cachedInventory);
-                InventoryPickupItemEvent pickupevent = new InventoryPickupItemEvent(hopperInventory, item);
-                Bukkit.getPluginManager().callEvent(pickupevent);
-                if (pickupevent.isCancelled())
+                InventoryPickupItemEvent pickupEvent = new InventoryPickupItemEvent(hopperInventory, item);
+                Bukkit.getPluginManager().callEvent(pickupEvent);
+                if (pickupEvent.isCancelled()) {
                     continue;
+                }
             }
 
             // try to add the items to the hopper
             int toAdd, added = hopperCache.addAny(itemStack, toAdd = getActualItemAmount(item));
-            if (added == 0)
+            if (added == 0) {
                 return;
+            }
 
             // items added ok!
-            if (added == toAdd)
+            if (added == toAdd) {
                 item.remove();
-            else {
+            } else {
                 // update the item's total
                 updateAmount(item, toAdd - added);
 
                 // wait before trying to add again
-                blacklist.add(item.getUniqueId());
-                Bukkit.getScheduler().runTaskLater(EpicHoppers.getInstance(),
-                        () -> blacklist.remove(item.getUniqueId()), 10L);
+                BLACKLIST.add(item.getUniqueId());
+                Bukkit.getScheduler().runTaskLater(this.plugin,
+                        () -> BLACKLIST.remove(item.getUniqueId()), 10L);
             }
 
             float xx = (float) (0 + (Math.random() * .1));
@@ -150,31 +155,33 @@ public class ModuleSuction extends Module {
     }
 
     private int getActualItemAmount(Item item) {
-        if (ultimateStacker) {
-            return com.songoda.ultimatestacker.utils.Methods.getActualItemAmount(item);
-        } else if (wildStacker)
+        if (ULTIMATE_STACKER) {
+            return UltimateStacker.getActualItemAmount(item);
+        } else if (WILD_STACKER) {
             return WildStackerAPI.getItemAmount(item);
-        else
+        } else {
             return item.getItemStack().getAmount();
+        }
 
     }
 
     private void updateAmount(Item item, int amount) {
-        if (ultimateStacker) {
+        if (ULTIMATE_STACKER) {
             UltimateStacker.updateItemAmount(item, item.getItemStack(), amount);
-        } else if (wildStacker)
+        } else if (WILD_STACKER) {
             WildStackerAPI.getStackedItem(item).setStackAmount(amount, true);
-        else
+        } else {
             item.getItemStack().setAmount(Math.min(amount, item.getItemStack().getMaxStackSize()));
+        }
     }
 
     public static boolean isBlacklisted(UUID uuid) {
-        return blacklist.contains(uuid);
+        return BLACKLIST.contains(uuid);
     }
 
     @Override
     public ItemStack getGUIButton(Hopper hopper) {
-        Locale locale = EpicHoppers.getInstance().getLocale();
+        Locale locale = this.plugin.getLocale();
         ItemStack item = CompatibleMaterial.CAULDRON.getItem();
         ItemMeta meta = item.getItemMeta();
         meta.setDisplayName(locale.getMessage("interface.hopper.suctiontitle").getMessage());
@@ -196,7 +203,7 @@ public class ModuleSuction extends Module {
             toggleEnabled(hopper);
         } else if (type == ClickType.RIGHT) {
             int setRadius = getRadius(hopper);
-            if (setRadius >= maxSearchRadius) {
+            if (setRadius >= this.maxSearchRadius) {
                 setRadius(hopper, 1);
             } else {
                 setRadius(hopper, ++setRadius);
@@ -216,7 +223,7 @@ public class ModuleSuction extends Module {
 
     private int getRadius(Hopper hopper) {
         Object foundRadius = getData(hopper, "radius");
-        return foundRadius == null ? maxSearchRadius : (int) foundRadius;
+        return foundRadius == null ? this.maxSearchRadius : (int) foundRadius;
     }
 
     private void setRadius(Hopper hopper, int radius) {
@@ -230,7 +237,9 @@ public class ModuleSuction extends Module {
 
     @Override
     public String getDescription() {
-        return EpicHoppers.getInstance().getLocale().getMessage("interface.hopper.suction")
-                .processPlaceholder("suction", maxSearchRadius).getMessage();
+        return this.plugin.getLocale()
+                .getMessage("interface.hopper.suction")
+                .processPlaceholder("suction", this.maxSearchRadius)
+                .getMessage();
     }
 }

src/main/java/com/songoda/epichoppers/hopper/teleport/TeleportHandler.java

@@ -21,44 +21,48 @@ import java.util.Map;
 import java.util.UUID;
 
 public class TeleportHandler {
-
     private final Map<UUID, Long> lastTeleports = new HashMap<>();
 
     private final EpicHoppers plugin;
 
     public TeleportHandler(EpicHoppers plugin) {
         this.plugin = plugin;
-        Bukkit.getScheduler().scheduleSyncRepeatingTask(plugin, this::teleportRunner, 0,
-                Settings.TELEPORT_TICKS.getLong());
+        Bukkit.getScheduler().scheduleSyncRepeatingTask(plugin, this::teleportRunner, 0, Settings.TELEPORT_TICKS.getLong());
     }
 
     private void teleportRunner() {
-        if (!plugin.getHopperManager().isReady())
+        if (!this.plugin.getHopperManager().isReady()) {
             return;
+        }
 
         for (World world : Bukkit.getWorlds()) {
             for (Entity entity : world.getEntities()) {
-                if (!(entity instanceof LivingEntity) || entity.getType() == EntityType.ARMOR_STAND)
+                if (!(entity instanceof LivingEntity) || entity.getType() == EntityType.ARMOR_STAND) {
                     continue;
+                }
 
                 if (!Settings.TELEPORT.getBoolean()
-                        || (entity instanceof Player && !entity.hasPermission("EpicHoppers.Teleport")))
+                        || (entity instanceof Player && !entity.hasPermission("EpicHoppers.Teleport"))) {
                     continue;
+                }
 
                 Location location = entity.getLocation().getBlock().getRelative(BlockFace.DOWN).getLocation();
 
-                if (!this.plugin.getHopperManager().isHopper(location))
+                if (!this.plugin.getHopperManager().isHopper(location)) {
                     continue;
+                }
 
                 Hopper hopper = this.plugin.getHopperManager().getHopper(location);
 
-                if (hopper.getTeleportTrigger() != TeleportTrigger.WALK_ON)
+                if (hopper.getTeleportTrigger() != TeleportTrigger.WALK_ON) {
                     continue;
+                }
 
                 if (this.lastTeleports.containsKey(entity.getUniqueId())) {
                     long duration = (new Date()).getTime() - new Date(this.lastTeleports.get(entity.getUniqueId())).getTime();
-                    if (duration <= 5 * 1000)
+                    if (duration <= 5 * 1000) {
                         continue;
+                    }
                 }
 
                 this.tpEntity(entity, hopper);
@@ -68,12 +72,14 @@ public class TeleportHandler {
     }
 
     public void tpEntity(Entity entity, Hopper hopper) {
-        if (hopper == null || !this.plugin.getHopperManager().isHopper(hopper.getLocation()))
+        if (hopper == null || !this.plugin.getHopperManager().isHopper(hopper.getLocation())) {
             return;
+        }
 
         Hopper lastHopper = this.getChain(hopper, 1);
-        if (!hopper.equals(lastHopper))
+        if (!hopper.equals(lastHopper)) {
             this.doTeleport(entity, lastHopper.getLocation());
+        }
     }
 
     /**
@@ -84,14 +90,16 @@ public class TeleportHandler {
      * @return The hopper at the end of the chain (or up to 15 in depth)
      */
     private Hopper getChain(Hopper lastHopper, int currentChainLength) {
-        if (currentChainLength > 15)
+        if (currentChainLength > 15) {
             return lastHopper;
+        }
 
         for (Location nextHopperLocation : lastHopper.getLinkedBlocks()) {
             if (nextHopperLocation.getBlock().getState() instanceof org.bukkit.block.Hopper) {
                 Hopper hopper = this.plugin.getHopperManager().getHopper(nextHopperLocation);
-                if (hopper != null)
+                if (hopper != null) {
                     return this.getChain(hopper, currentChainLength + 1);
+                }
             }
         }
 

src/main/java/com/songoda/epichoppers/hopper/teleport/TeleportTrigger.java

@@ -1,7 +1,5 @@
 package com.songoda.epichoppers.hopper.teleport;
 
 public enum TeleportTrigger {
-
     DISABLED, WALK_ON, SNEAK
-
 }

src/main/java/com/songoda/epichoppers/listeners/BlockListeners.java

@@ -24,6 +24,8 @@ import org.bukkit.event.block.BlockPlaceEvent;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.permissions.PermissionAttachmentInfo;
 
+import java.util.Objects;
+
 /**
  * Created by songoda on 3/14/2017.
  */
@@ -40,63 +42,73 @@ public class BlockListeners implements Listener {
     public void onBlockPlace(BlockPlaceEvent e) {
         Player player = e.getPlayer();
 
-        if (e.getBlock().getType() != Material.HOPPER)
+        if (e.getBlock().getType() != Material.HOPPER) {
             return;
+        }
 
-        if (Settings.DISABLED_WORLDS.getStringList().contains(player.getWorld().getName()))
+        if (Settings.DISABLED_WORLDS.getStringList().contains(player.getWorld().getName())) {
             return;
+        }
 
         int amt = count(e.getBlock().getChunk());
 
         int max = maxHoppers(player);
 
         if (max != -1 && amt > max) {
-            player.sendMessage(plugin.getLocale().getMessage("event.hopper.toomany").processPlaceholder("amount", max).getMessage());
+            player.sendMessage(this.plugin.getLocale().getMessage("event.hopper.toomany").processPlaceholder("amount", max).getMessage());
             e.setCancelled(true);
             return;
         }
 
         ItemStack item = e.getItemInHand().clone();
 
-        if (Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !plugin.getLevelManager().isEpicHopper(item))
+        if (Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !this.plugin.getLevelManager().isEpicHopper(item)) {
             return;
+        }
 
-        if (!plugin.getHopperManager().isReady()) {
-            player.sendMessage(plugin.getLocale().getMessage("event.hopper.notready").getMessage());
+        if (!this.plugin.getHopperManager().isReady()) {
+            player.sendMessage(this.plugin.getLocale().getMessage("event.hopper.notready").getMessage());
             e.setCancelled(true);
             return;
         }
 
-        Hopper hopper = plugin.getHopperManager().addHopper(
+        Hopper hopper = this.plugin.getHopperManager().addHopper(
                 new HopperBuilder(e.getBlock())
-                        .setLevel(plugin.getLevelManager().getLevel(item))
+                        .setLevel(this.plugin.getLevelManager().getLevel(item))
                         .setPlacedBy(player)
                         .setLastPlayerOpened(player).build());
 
         HopperPlaceEvent hopperPlaceEvent = new HopperPlaceEvent(player, hopper);
         Bukkit.getPluginManager().callEvent(hopperPlaceEvent);
 
-        EpicHoppers.getInstance().getDataManager().createHopper(hopper);
+        this.plugin.getDataManager().createHopper(hopper);
     }
 
     private int maxHoppers(Player player) {
         int limit = -1;
         for (PermissionAttachmentInfo permissionAttachmentInfo : player.getEffectivePermissions()) {
-            if (!permissionAttachmentInfo.getPermission().toLowerCase().startsWith("epichoppers.limit")) continue;
+            if (!permissionAttachmentInfo.getPermission().toLowerCase().startsWith("epichoppers.limit")) {
+                continue;
+            }
             int num = Integer.parseInt(permissionAttachmentInfo.getPermission().split("\\.")[2]);
-            if (num > limit)
+            if (num > limit) {
                 limit = num;
+            }
+        }
+        if (limit == -1) {
+            limit = Settings.MAX_CHUNK.getInt();
         }
-        if (limit == -1) limit = Settings.MAX_CHUNK.getInt();
         return limit;
     }
 
-    private int count(Chunk c) {
+    private int count(Chunk chunk) {
         int count = 0;
         for (int x = 0; x < 16; x++) {
             for (int z = 0; z < 16; z++) {
-                for (int y = getMinHeight(c.getWorld()); y < c.getWorld().getMaxHeight(); y++) {
-                    if (c.getBlock(x, y, z).getType() == Material.HOPPER) count++;
+                for (int y = getMinHeight(chunk.getWorld()); y < chunk.getWorld().getMaxHeight(); y++) {
+                    if (chunk.getBlock(x, y, z).getType() == Material.HOPPER) {
+                        count++;
+                    }
                 }
             }
         }
@@ -108,18 +120,21 @@ public class BlockListeners implements Listener {
         Block block = event.getBlock();
         Player player = event.getPlayer();
 
-        if (event.getBlock().getType() != Material.HOPPER) return;
+        if (event.getBlock().getType() != Material.HOPPER) {
+            return;
+        }
 
-        if (!plugin.getHopperManager().isReady()) {
-            player.sendMessage(plugin.getLocale().getMessage("event.hopper.notready").getMessage());
+        if (!this.plugin.getHopperManager().isReady()) {
+            player.sendMessage(this.plugin.getLocale().getMessage("event.hopper.notready").getMessage());
             event.setCancelled(true);
             return;
         }
 
-        if (Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !plugin.getHopperManager().isHopper(block.getLocation()))
+        if (Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !this.plugin.getHopperManager().isHopper(block.getLocation())) {
             return;
+        }
 
-        Hopper hopper = plugin.getHopperManager().getHopper(block);
+        Hopper hopper = this.plugin.getHopperManager().getHopper(block);
 
         GUIFilter.compileOpenGuiFilter(hopper);
         GUIAutoSellFilter.compileOpenAutoSellFilter(hopper);
@@ -131,7 +146,7 @@ public class BlockListeners implements Listener {
             Bukkit.getPluginManager().callEvent(hopperBreakEvent);
 
             event.setCancelled(true);
-            ItemStack item = plugin.newHopperItem(level);
+            ItemStack item = this.plugin.newHopperItem(level);
 
             hopper.dropItems();
 
@@ -142,26 +157,26 @@ public class BlockListeners implements Listener {
         hopper.forceClose();
 
         hopper.getFilter().getWhiteList().stream()
-                .filter(m -> m != null)
+                .filter(Objects::nonNull)
                 .forEach(m -> event.getBlock().getWorld().dropItemNaturally(event.getBlock().getLocation(), m));
         hopper.getFilter().getBlackList().stream()
-                .filter(m -> m != null)
+                .filter(Objects::nonNull)
                 .forEach(m -> event.getBlock().getWorld().dropItemNaturally(event.getBlock().getLocation(), m));
         hopper.getFilter().getVoidList().stream().
-                filter(m -> m != null)
+                filter(Objects::nonNull)
                 .forEach(m -> event.getBlock().getWorld().dropItemNaturally(event.getBlock().getLocation(), m));
 
         hopper.getFilter().getAutoSellWhiteList().stream()
-                .filter(m -> m != null)
+                .filter(Objects::nonNull)
                 .forEach(m -> event.getBlock().getWorld().dropItemNaturally(event.getBlock().getLocation(), m));
         hopper.getFilter().getAutoSellBlackList().stream()
-                .filter(m -> m != null)
+                .filter(Objects::nonNull)
                 .forEach(m -> event.getBlock().getWorld().dropItemNaturally(event.getBlock().getLocation(), m));
 
-        plugin.getHopperManager().removeHopper(block.getLocation());
-        plugin.getDataManager().deleteHopper(hopper);
+        this.plugin.getHopperManager().removeHopper(block.getLocation());
+        this.plugin.getDataManager().deleteHopper(hopper);
 
-        plugin.getPlayerDataManager().getPlayerData(player).setSyncType(null);
+        this.plugin.getPlayerDataManager().getPlayerData(player).setSyncType(null);
     }
 
     public int getMinHeight(World world) {

src/main/java/com/songoda/epichoppers/listeners/EntityListeners.java

@@ -7,10 +7,10 @@ import org.bukkit.event.Listener;
 import org.bukkit.event.player.PlayerPickupItemEvent;
 
 public class EntityListeners implements Listener {
-
     @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
     public void onPlayerPickup(PlayerPickupItemEvent event) {
-        if (ModuleSuction.isBlacklisted(event.getItem().getUniqueId()))
+        if (ModuleSuction.isBlacklisted(event.getItem().getUniqueId())) {
             event.setCancelled(true);
+        }
     }
 }

src/main/java/com/songoda/epichoppers/listeners/HopperListeners.java

@@ -20,11 +20,7 @@ import org.bukkit.event.inventory.InventoryMoveItemEvent;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
 
-/**
- * Created by songoda on 4/18/2017.
- */
 public class HopperListeners implements Listener {
-
     private final EpicHoppers plugin;
 
     public HopperListeners(EpicHoppers plugin) {
@@ -40,15 +36,17 @@ public class HopperListeners implements Listener {
         Location sourceLocation = source.getHolder() instanceof BlockState ? ((BlockState) source.getHolder()).getLocation() : null;
         Location destinationLocation = destination.getHolder() instanceof BlockState ? ((BlockState) destination.getHolder()).getLocation() : null;
 
-        if (sourceLocation != null && Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !plugin.getHopperManager().isHopper(sourceLocation))
+        if (sourceLocation != null && Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !this.plugin.getHopperManager().isHopper(sourceLocation)) {
             return;
+        }
 
         // Hopper minecarts should be able to take care of themselves
         // Let EpicHoppers take over if the hopper is pointing down though
         if (destination.getHolder() instanceof HopperMinecart
                 && source.getHolder() instanceof org.bukkit.block.Hopper
-                && HopperDirection.getDirection(((org.bukkit.block.Hopper) source.getHolder()).getRawData()) != HopperDirection.DOWN)
+                && HopperDirection.getDirection(((org.bukkit.block.Hopper) source.getHolder()).getRawData()) != HopperDirection.DOWN) {
             return;
+        }
 
         // Shulker boxes have a mind of their own and relentlessly steal items from hoppers
         if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_11)
@@ -66,14 +64,16 @@ public class HopperListeners implements Listener {
 
         // Special cases when a hopper is picking up items
         if (destination.getHolder() instanceof org.bukkit.block.Hopper) {
-            if (destinationLocation != null && Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !plugin.getHopperManager().isHopper(destinationLocation))
+            if (destinationLocation != null && Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !this.plugin.getHopperManager().isHopper(destinationLocation)) {
                 return;
+            }
 
             // Calling HopperManager#getHopper() automatically creates a new Hopper and we don't need to iterate over default-valued hoppers
-            if (!plugin.getHopperManager().isHopper(destinationLocation))
+            if (!this.plugin.getHopperManager().isHopper(destinationLocation)) {
                 return;
+            }
 
-            Hopper toHopper = plugin.getHopperManager().getHopper(destinationLocation);
+            Hopper toHopper = this.plugin.getHopperManager().getHopper(destinationLocation);
             // minecraft 1.8 doesn't have a method to get the hopper's location from the inventory, so we use the holder instead
             final ItemStack toMove = event.getItem();
 
@@ -153,11 +153,13 @@ public class HopperListeners implements Listener {
             }
         }
 
-        if (!(source.getHolder() instanceof org.bukkit.block.Hopper))
+        if (!(source.getHolder() instanceof org.bukkit.block.Hopper)) {
             return;
+        }
 
-        if (destinationLocation == null)
+        if (destinationLocation == null) {
             return;
+        }
 
         // Handle hopper push events elsewhere
         event.setCancelled(true);

src/main/java/com/songoda/epichoppers/listeners/InteractListeners.java

@@ -22,11 +22,7 @@ import org.bukkit.event.player.PlayerInteractEvent;
 import org.bukkit.event.player.PlayerToggleSneakEvent;
 import org.bukkit.inventory.InventoryHolder;
 
-/**
- * Created by songoda on 3/14/2017.
- */
 public class InteractListeners implements Listener {
-
     private final EpicHoppers plugin;
 
     public InteractListeners(EpicHoppers plugin) {
@@ -36,17 +32,19 @@ public class InteractListeners implements Listener {
     @EventHandler
     public void onPlayerToggleSneakEvent(PlayerToggleSneakEvent event) {
         Player player = event.getPlayer();
-        if (player.isSneaking() && plugin.getHopperManager().isReady()) {
+        if (player.isSneaking() && this.plugin.getHopperManager().isReady()) {
             Location location = player.getLocation().getBlock().getRelative(BlockFace.SELF).getLocation();
             Location down = location.getBlock().getRelative(BlockFace.DOWN).getLocation();
-            if (plugin.getHopperManager().isHopper(down)) {
-                Hopper hopper = plugin.getHopperManager().getHopper(down);
-                if (hopper.getTeleportTrigger() == TeleportTrigger.SNEAK)
-                    plugin.getTeleportHandler().tpEntity(player, hopper);
-            } else if (plugin.getHopperManager().isHopper(location)) {
-                Hopper hopper = plugin.getHopperManager().getHopper(location);
-                if (hopper.getTeleportTrigger() == TeleportTrigger.SNEAK)
-                    plugin.getTeleportHandler().tpEntity(player, hopper);
+            if (this.plugin.getHopperManager().isHopper(down)) {
+                Hopper hopper = this.plugin.getHopperManager().getHopper(down);
+                if (hopper.getTeleportTrigger() == TeleportTrigger.SNEAK) {
+                    this.plugin.getTeleportHandler().tpEntity(player, hopper);
+                }
+            } else if (this.plugin.getHopperManager().isHopper(location)) {
+                Hopper hopper = this.plugin.getHopperManager().getHopper(location);
+                if (hopper.getTeleportTrigger() == TeleportTrigger.SNEAK) {
+                    this.plugin.getTeleportHandler().tpEntity(player, hopper);
+                }
             }
         }
     }
@@ -58,12 +56,12 @@ public class InteractListeners implements Listener {
                 || event.getClickedBlock() == null
                 || player.isSneaking()
                 || !player.hasPermission("EpicHoppers.overview")
-                || !(event.getClickedBlock().getState() instanceof InventoryHolder || event.getClickedBlock().getType().equals(Material.ENDER_CHEST))) {
+                || !(event.getClickedBlock().getState() instanceof InventoryHolder || event.getClickedBlock().getType() == Material.ENDER_CHEST)) {
             return;
         }
 
         if (Settings.USE_PROTECTION_PLUGINS.getBoolean() && ProtectionManager.canInteract(player, event.getClickedBlock().getLocation()) && WorldGuardHook.isInteractAllowed(event.getClickedBlock().getLocation())) {
-            player.sendMessage(plugin.getLocale().getMessage("event.general.protected").getPrefixedMessage());
+            player.sendMessage(this.plugin.getLocale().getMessage("event.general.protected").getPrefixedMessage());
             return;
         }
 
@@ -71,26 +69,28 @@ public class InteractListeners implements Listener {
             SkyBlock skyBlock = SkyBlock.getInstance();
 
             if (skyBlock.getWorldManager().isIslandWorld(event.getPlayer().getWorld()) &&
-                    !skyBlock.getPermissionManager().hasPermission(event.getPlayer(), skyBlock.getIslandManager().getIslandAtLocation(event.getClickedBlock().getLocation()), "EpicHoppers"))
+                    !skyBlock.getPermissionManager().hasPermission(event.getPlayer(), skyBlock.getIslandManager().getIslandAtLocation(event.getClickedBlock().getLocation()), "EpicHoppers")) {
                 return;
+            }
         }
 
-        PlayerData playerData = plugin.getPlayerDataManager().getPlayerData(player);
+        PlayerData playerData = this.plugin.getPlayerDataManager().getPlayerData(player);
 
         if (playerData.getSyncType() == null) {
             if (event.getClickedBlock().getType() == Material.HOPPER) {
-                if (!plugin.getHopperManager().isReady()) {
-                    player.sendMessage(plugin.getLocale().getMessage("event.hopper.notready").getMessage());
+                if (!this.plugin.getHopperManager().isReady()) {
+                    player.sendMessage(this.plugin.getLocale().getMessage("event.hopper.notready").getMessage());
                     event.setCancelled(true);
                     return;
                 }
 
-                if (Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !plugin.getHopperManager().isHopper(event.getClickedBlock().getLocation()))
+                if (Settings.ALLOW_NORMAL_HOPPERS.getBoolean() && !this.plugin.getHopperManager().isHopper(event.getClickedBlock().getLocation())) {
                     return;
+                }
 
-                Hopper hopper = plugin.getHopperManager().getHopper(event.getClickedBlock());
+                Hopper hopper = this.plugin.getHopperManager().getHopper(event.getClickedBlock());
                 if (!player.getInventory().getItemInHand().getType().name().contains("PICKAXE")) {
-                    hopper.overview(plugin.getGuiManager(), player);
+                    hopper.overview(this.plugin.getGuiManager(), player);
                     event.setCancelled(true);
                     return;
                 }
@@ -98,15 +98,14 @@ public class InteractListeners implements Listener {
             return;
         }
 
-        if (event.getClickedBlock().getState() instanceof InventoryHolder
-                || (event.getClickedBlock().getType().equals(Material.ENDER_CHEST)
-                && Settings.ENDERCHESTS.getBoolean())) {
+        if (event.getClickedBlock().getState() instanceof InventoryHolder ||
+                (event.getClickedBlock().getType() == Material.ENDER_CHEST && Settings.ENDERCHESTS.getBoolean())) {
             Hopper hopper = playerData.getLastHopper();
             if (event.getClickedBlock().getLocation().equals(playerData.getLastHopper().getLocation())) {
                 if (!hopper.getLinkedBlocks().isEmpty()) {
-                    plugin.getLocale().getMessage("event.hopper.syncfinish").sendPrefixedMessage(player);
+                    this.plugin.getLocale().getMessage("event.hopper.syncfinish").sendPrefixedMessage(player);
                 } else {
-                    plugin.getLocale().getMessage("event.hopper.synccanceled").sendPrefixedMessage(player);
+                    this.plugin.getLocale().getMessage("event.hopper.synccanceled").sendPrefixedMessage(player);
                 }
                 hopper.cancelSync(player);
             } else if (playerData.getSyncType() != null) {

src/main/java/com/songoda/epichoppers/listeners/InventoryListeners.java

@@ -8,27 +8,24 @@ import org.bukkit.event.inventory.InventoryClickEvent;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.ItemStack;
 
-/**
- * Created by songoda on 3/14/2017.
- */
 public class InventoryListeners implements Listener {
-
     @EventHandler
     public void onInventoryClick(InventoryClickEvent event) {
-        if (event.getCurrentItem() == null) return;
+        if (event.getCurrentItem() == null ||
+                event.getRawSlot() > event.getView().getTopInventory().getSize() - 1 ||
+                !event.getCurrentItem().hasItemMeta()) {
+            return;
+        }
+        if (event.getSlot() == 64537 ||
+                event.getInventory().getType() != InventoryType.ANVIL ||
+                event.getAction() == InventoryAction.NOTHING ||
+                event.getCurrentItem().getType() == Material.AIR) {
+            return;
+        }
 
-        if (event.getRawSlot() > event.getView().getTopInventory().getSize() - 1) return;
-
-        if (!event.getCurrentItem().hasItemMeta()) return;
-
-        if (event.getSlot() != 64537
-                && event.getInventory().getType() == InventoryType.ANVIL
-                && event.getAction() != InventoryAction.NOTHING
-                && event.getCurrentItem().getType() != Material.AIR) {
-            ItemStack item = event.getCurrentItem();
-            if (item.getType() == Material.HOPPER) {
-                event.setCancelled(true);
-            }
+        ItemStack item = event.getCurrentItem();
+        if (item.getType() == Material.HOPPER) {
+            event.setCancelled(true);
         }
     }
 }

src/main/java/com/songoda/epichoppers/player/PlayerData.java

@@ -3,13 +3,11 @@ package com.songoda.epichoppers.player;
 import com.songoda.epichoppers.hopper.Hopper;
 
 public class PlayerData {
-
     private Hopper lastHopper = null;
-
     private SyncType syncType = null; // Null means off.
 
     public Hopper getLastHopper() {
-        return lastHopper;
+        return this.lastHopper;
     }
 
     public void setLastHopper(Hopper lastHopper) {
@@ -17,7 +15,7 @@ public class PlayerData {
     }
 
     public SyncType getSyncType() {
-        return syncType;
+        return this.syncType;
     }
 
     public void setSyncType(SyncType syncType) {

src/main/java/com/songoda/epichoppers/player/PlayerDataManager.java

@@ -9,11 +9,10 @@ import java.util.Map;
 import java.util.UUID;
 
 public class PlayerDataManager {
-
     private final Map<UUID, PlayerData> registeredPlayers = new HashMap<>();
 
     private PlayerData getPlayerData(UUID uuid) {
-        return registeredPlayers.computeIfAbsent(uuid, u -> new PlayerData());
+        return this.registeredPlayers.computeIfAbsent(uuid, u -> new PlayerData());
     }
 
     public PlayerData getPlayerData(Player player) {
@@ -21,6 +20,6 @@ public class PlayerDataManager {
     }
 
     public Collection<PlayerData> getRegisteredPlayers() {
-        return Collections.unmodifiableCollection(registeredPlayers.values());
+        return Collections.unmodifiableCollection(this.registeredPlayers.values());
     }
 }

src/main/java/com/songoda/epichoppers/player/SyncType.java

@@ -1,8 +1,6 @@
 package com.songoda.epichoppers.player;
 
 public enum SyncType {
-
     REGULAR,
     FILTERED
-
 }

src/main/java/com/songoda/epichoppers/settings/Settings.java

@@ -10,148 +10,146 @@ import java.util.Arrays;
 import java.util.stream.Collectors;
 
 public class Settings {
+    private static final Config CONFIG = EpicHoppers.getPlugin(EpicHoppers.class).getCoreConfig();
 
-    private static final Config config = EpicHoppers.getInstance().getCoreConfig();
-
-    public static final ConfigSetting HOPPER_UPGRADING = new ConfigSetting(config, "Main.Allow hopper Upgrading", true,
+    public static final ConfigSetting HOPPER_UPGRADING = new ConfigSetting(CONFIG, "Main.Allow hopper Upgrading", true,
             "Should hoppers be upgradable?");
 
-    public static final ConfigSetting UPGRADE_WITH_ECONOMY = new ConfigSetting(config, "Main.Upgrade With Economy", true,
+    public static final ConfigSetting UPGRADE_WITH_ECONOMY = new ConfigSetting(CONFIG, "Main.Upgrade With Economy", true,
             "Should you be able to upgrade hoppers with economy?");
 
-    public static final ConfigSetting UPGRADE_WITH_XP = new ConfigSetting(config, "Main.Upgrade With XP", true,
+    public static final ConfigSetting UPGRADE_WITH_XP = new ConfigSetting(CONFIG, "Main.Upgrade With XP", true,
             "Should you be able to upgrade hoppers with experience?");
 
-    public static final ConfigSetting ALLOW_NORMAL_HOPPERS = new ConfigSetting(config, "Main.Allow Normal Hoppers", false,
+    public static final ConfigSetting ALLOW_NORMAL_HOPPERS = new ConfigSetting(CONFIG, "Main.Allow Normal Hoppers", false,
             "Should natural hoppers not be epic hoppers?");
 
-    public static final ConfigSetting DISABLED_WORLDS = new ConfigSetting(config, "Main.Disabled Worlds",
+    public static final ConfigSetting DISABLED_WORLDS = new ConfigSetting(CONFIG, "Main.Disabled Worlds",
             Arrays.asList("example1", "example2"),
             "Worlds where epic hoppers cannot be placed.",
             "Any placed Epic Hopper will just be converted to a normal one.");
 
-    public static final ConfigSetting TELEPORT = new ConfigSetting(config, "Main.Allow Players To Teleport Through Hoppers", true,
+    public static final ConfigSetting TELEPORT = new ConfigSetting(CONFIG, "Main.Allow Players To Teleport Through Hoppers", true,
             "Should players be able to teleport through hoppers?");
 
-    public static final ConfigSetting ENDERCHESTS = new ConfigSetting(config, "Main.Support Enderchests", true,
+    public static final ConfigSetting ENDERCHESTS = new ConfigSetting(CONFIG, "Main.Support Enderchests", true,
             "Should hoppers dump items into a player enderchests?");
 
-    public static final ConfigSetting UPGRADE_PARTICLE_TYPE = new ConfigSetting(config, "Main.Upgrade Particle Type", "SPELL_WITCH",
+    public static final ConfigSetting UPGRADE_PARTICLE_TYPE = new ConfigSetting(CONFIG, "Main.Upgrade Particle Type", "SPELL_WITCH",
             "The type of particle shown when a hopper is upgraded.");
 
-    public static final ConfigSetting HOP_TICKS = new ConfigSetting(config, "Main.Amount of Ticks Between Hops", 8L,
+    public static final ConfigSetting HOP_TICKS = new ConfigSetting(CONFIG, "Main.Amount of Ticks Between Hops", 8L,
             "The amount of ticks between hopper transfers.");
 
-    public static final ConfigSetting AUTOSAVE = new ConfigSetting(config, "Main.Auto Save Interval In Seconds", 15,
+    public static final ConfigSetting AUTOSAVE = new ConfigSetting(CONFIG, "Main.Auto Save Interval In Seconds", 15,
             "The amount of time in between saving to file.",
             "This is purely a safety function to prevent against unplanned crashes or",
             "restarts. With that said it is advised to keep this enabled.",
             "If however you enjoy living on the edge, feel free to turn it off.");
 
-    public static final ConfigSetting TELEPORT_TICKS = new ConfigSetting(config, "Main.Amount of Ticks Between Teleport", 10L,
+    public static final ConfigSetting TELEPORT_TICKS = new ConfigSetting(CONFIG, "Main.Amount of Ticks Between Teleport", 10L,
             "The cooldown between teleports. It prevents players",
             "from getting stuck in a teleport loop.");
 
-    public static final ConfigSetting LINK_TIMEOUT = new ConfigSetting(config, "Main.Timeout When Syncing Hoppers", 300L,
+    public static final ConfigSetting LINK_TIMEOUT = new ConfigSetting(CONFIG, "Main.Timeout When Syncing Hoppers", 300L,
             "The amount of time in ticks a player has between hitting the hopper",
             "Link button and performing the link. When the time is up the link event is canceled.");
 
-    public static final ConfigSetting MAX_CHUNK = new ConfigSetting(config, "Main.Max Hoppers Per Chunk", -1,
+    public static final ConfigSetting MAX_CHUNK = new ConfigSetting(CONFIG, "Main.Max Hoppers Per Chunk", -1,
             "The maximum amount of hoppers per chunk.");
 
-    public static final ConfigSetting USE_PROTECTION_PLUGINS = new ConfigSetting(config, "Main.Use Protection Plugins", true,
+    public static final ConfigSetting USE_PROTECTION_PLUGINS = new ConfigSetting(CONFIG, "Main.Use Protection Plugins", true,
             "Should we use protection plugins?");
 
-    public static final ConfigSetting BLOCKBREAK_PARTICLE = new ConfigSetting(config, "Main.BlockBreak Particle Type", "LAVA",
+    public static final ConfigSetting BLOCKBREAK_PARTICLE = new ConfigSetting(CONFIG, "Main.BlockBreak Particle Type", "LAVA",
             "The particle shown when the block break module performs a block break.");
 
-    public static final ConfigSetting BLOCKBREAK_BLACKLIST = new ConfigSetting(config, "Main.BlockBreak Blacklisted Blocks",
+    public static final ConfigSetting BLOCKBREAK_BLACKLIST = new ConfigSetting(CONFIG, "Main.BlockBreak Blacklisted Blocks",
             Arrays.asList("BEDROCK", "END_PORTAL", "ENDER_PORTAL", "END_PORTAL_FRAME", "ENDER_PORTAL_FRAME", "PISTON_HEAD", "PISTON_EXTENSION", "RAIL", "RAILS", "ACTIVATOR_RAIL", "DETECTOR_RAIL", "POWERED_RAIL"),
             "Anything listed here will not be broken by the block break module.");
 
-    public static final ConfigSetting ALLOW_BLOCKBREAK_CONTAINERS = new ConfigSetting(config, "Main.Allow BlockBreak Containers", false,
+    public static final ConfigSetting ALLOW_BLOCKBREAK_CONTAINERS = new ConfigSetting(CONFIG, "Main.Allow BlockBreak Containers", false,
             "Allow BlockBreak to break containers.");
 
-    public static final ConfigSetting AUTOCRAFT_JAM_EJECT = new ConfigSetting(config, "Main.AutoCraft Jam Eject", false,
+    public static final ConfigSetting AUTOCRAFT_JAM_EJECT = new ConfigSetting(CONFIG, "Main.AutoCraft Jam Eject", false,
             "AutoCraft module needs a free slot to craft items with.",
             "Normally, crafting hoppers won't grab items that would fill that slot.",
             "This option ejects items if that last slot is forcibly filled");
 
-    public static final ConfigSetting AUTOCRAFT_BLACKLIST = new ConfigSetting(config, "Main.AutoCraft Blacklist", Arrays.asList("BEDROCK", "EGG"),
+    public static final ConfigSetting AUTOCRAFT_BLACKLIST = new ConfigSetting(CONFIG, "Main.AutoCraft Blacklist", Arrays.asList("BEDROCK", "EGG"),
             "Anything listed here will not be able to be auto crafted.");
 
-    public static final ConfigSetting AUTOSELL_PRICES = new ConfigSetting(config, "Main.AutoSell Prices",
+    public static final ConfigSetting AUTOSELL_PRICES = new ConfigSetting(CONFIG, "Main.AutoSell Prices",
             Arrays.asList("STONE,0.50", "COBBLESTONE,0.20", "IRON_ORE,0.35", "COAL_ORE,0.20"),
             "These are the prices used by the auto sell module.");
 
-    public static final ConfigSetting AUTOSELL_SHOPGUIPLUS = new ConfigSetting(config, "Main.Use ShopGuiPlus for Prices", false,
+    public static final ConfigSetting AUTOSELL_SHOPGUIPLUS = new ConfigSetting(CONFIG, "Main.Use ShopGuiPlus for Prices", false,
             "Should prices be grabbed from ShopGuiPlus?",
             "If ShopGuiPlus is not enabled or the player is offline the default price list will be used (or EconomyShopGUI if enabled).",
             "If this is something that you do not want then you should empty the default list.");
 
-    public static final ConfigSetting AUTOSELL_ECONOMY_SHOP_GUI = new ConfigSetting(config, "Main.Use EconomyShopGUI for Prices", false,
+    public static final ConfigSetting AUTOSELL_ECONOMY_SHOP_GUI = new ConfigSetting(CONFIG, "Main.Use EconomyShopGUI for Prices", false,
             "Should prices be grabbed from EconomyShopGUI?",
             "If 'Use ShopGuiPlus for Prices' is enabled and the player is online, this will be ignored.");
 
-    public static final ConfigSetting ECONOMY_PLUGIN = new ConfigSetting(config, "Main.Economy", EconomyManager.getEconomy() == null ? "Vault" : EconomyManager.getEconomy().getName(),
+    public static final ConfigSetting ECONOMY_PLUGIN = new ConfigSetting(CONFIG, "Main.Economy", EconomyManager.getEconomy() == null ? "Vault" : EconomyManager.getEconomy().getName(),
             "Which economy plugin should be used?",
             "Supported plugins you have installed: \"" + EconomyManager.getManager().getRegisteredPlugins().stream().collect(Collectors.joining("\", \"")) + "\".");
 
-    public static final ConfigSetting EMIT_INVENTORYPICKUPITEMEVENT = new ConfigSetting(config, "Main.Emit InventoryPickupItemEvent", false,
+    public static final ConfigSetting EMIT_INVENTORYPICKUPITEMEVENT = new ConfigSetting(CONFIG, "Main.Emit InventoryPickupItemEvent", false,
             "This event is used by other plugin to modify or monitor the behavior when a hopper picks up items on the ground.",
             "However it is a high frequency event and may have an impact on your server performance which is why it is disabled by default.",
             "If you absolutely need this enable it but be aware of the potential performance impact.");
 
-    public static final ConfigSetting ECO_ICON = new ConfigSetting(config, "Interfaces.Economy Icon", "SUNFLOWER");
-    public static final ConfigSetting XP_ICON = new ConfigSetting(config, "Interfaces.XP Icon", "EXPERIENCE_BOTTLE");
+    public static final ConfigSetting ECO_ICON = new ConfigSetting(CONFIG, "Interfaces.Economy Icon", "SUNFLOWER");
+    public static final ConfigSetting XP_ICON = new ConfigSetting(CONFIG, "Interfaces.XP Icon", "EXPERIENCE_BOTTLE");
 
-    public static final ConfigSetting GLASS_TYPE_1 = new ConfigSetting(config, "Interfaces.Glass Type 1", "GRAY_STAINED_GLASS_PANE");
-    public static final ConfigSetting GLASS_TYPE_2 = new ConfigSetting(config, "Interfaces.Glass Type 2", "BLUE_STAINED_GLASS_PANE");
-    public static final ConfigSetting GLASS_TYPE_3 = new ConfigSetting(config, "Interfaces.Glass Type 3", "LIGHT_BLUE_STAINED_GLASS_PANE");
+    public static final ConfigSetting GLASS_TYPE_1 = new ConfigSetting(CONFIG, "Interfaces.Glass Type 1", "GRAY_STAINED_GLASS_PANE");
+    public static final ConfigSetting GLASS_TYPE_2 = new ConfigSetting(CONFIG, "Interfaces.Glass Type 2", "BLUE_STAINED_GLASS_PANE");
+    public static final ConfigSetting GLASS_TYPE_3 = new ConfigSetting(CONFIG, "Interfaces.Glass Type 3", "LIGHT_BLUE_STAINED_GLASS_PANE");
 
-    public static final ConfigSetting LANGUGE_MODE = new ConfigSetting(config, "System.Language Mode", "en_US",
+    public static final ConfigSetting LANGUGE_MODE = new ConfigSetting(CONFIG, "System.Language Mode", "en_US",
             "The enabled language file.",
             "More language files (if available) can be found in the plugins data folder.");
 
-    public static final ConfigSetting MYSQL_ENABLED = new ConfigSetting(config, "MySQL.Enabled", false, "Set to 'true' to use MySQL instead of SQLite for data storage.");
-    public static final ConfigSetting MYSQL_HOSTNAME = new ConfigSetting(config, "MySQL.Hostname", "localhost");
-    public static final ConfigSetting MYSQL_PORT = new ConfigSetting(config, "MySQL.Port", 3306);
-    public static final ConfigSetting MYSQL_DATABASE = new ConfigSetting(config, "MySQL.Database", "your-database");
-    public static final ConfigSetting MYSQL_USERNAME = new ConfigSetting(config, "MySQL.Username", "user");
-    public static final ConfigSetting MYSQL_PASSWORD = new ConfigSetting(config, "MySQL.Password", "pass");
-    public static final ConfigSetting MYSQL_USE_SSL = new ConfigSetting(config, "MySQL.Use SSL", false);
-    public static final ConfigSetting MYSQL_POOL_SIZE = new ConfigSetting(config, "MySQL.Pool Size", 3, "Determines the number of connections the pool is using. Increase this value if you are getting timeout errors when more players online.");
-
+    public static final ConfigSetting MYSQL_ENABLED = new ConfigSetting(CONFIG, "MySQL.Enabled", false, "Set to 'true' to use MySQL instead of SQLite for data storage.");
+    public static final ConfigSetting MYSQL_HOSTNAME = new ConfigSetting(CONFIG, "MySQL.Hostname", "localhost");
+    public static final ConfigSetting MYSQL_PORT = new ConfigSetting(CONFIG, "MySQL.Port", 3306);
+    public static final ConfigSetting MYSQL_DATABASE = new ConfigSetting(CONFIG, "MySQL.Database", "your-database");
+    public static final ConfigSetting MYSQL_USERNAME = new ConfigSetting(CONFIG, "MySQL.Username", "user");
+    public static final ConfigSetting MYSQL_PASSWORD = new ConfigSetting(CONFIG, "MySQL.Password", "pass");
+    public static final ConfigSetting MYSQL_USE_SSL = new ConfigSetting(CONFIG, "MySQL.Use SSL", false);
+    public static final ConfigSetting MYSQL_POOL_SIZE = new ConfigSetting(CONFIG, "MySQL.Pool Size", 3, "Determines the number of connections the pool is using. Increase this value if you are getting timeout errors when more players online.");
 
     /**
      * In order to set dynamic economy comment correctly, this needs to be
      * called after EconomyManager load
      */
     public static void setupConfig() {
-        config.load();
-        config.setAutoremove(true).setAutosave(true);
+        CONFIG.load();
+        CONFIG.setAutoremove(true).setAutosave(true);
 
         // convert glass pane settings
         int color;
         if ((color = GLASS_TYPE_1.getInt(-1)) != -1) {
-            config.set(GLASS_TYPE_1.getKey(), CompatibleMaterial.getGlassPaneColor(color).name());
+            CONFIG.set(GLASS_TYPE_1.getKey(), CompatibleMaterial.getGlassPaneColor(color).name());
         }
         if ((color = GLASS_TYPE_2.getInt(-1)) != -1) {
-            config.set(GLASS_TYPE_2.getKey(), CompatibleMaterial.getGlassPaneColor(color).name());
+            CONFIG.set(GLASS_TYPE_2.getKey(), CompatibleMaterial.getGlassPaneColor(color).name());
         }
         if ((color = GLASS_TYPE_3.getInt(-1)) != -1) {
-            config.set(GLASS_TYPE_3.getKey(), CompatibleMaterial.getGlassPaneColor(color).name());
+            CONFIG.set(GLASS_TYPE_3.getKey(), CompatibleMaterial.getGlassPaneColor(color).name());
         }
 
         // convert economy settings
-        if (config.getBoolean("Economy.Use Vault Economy") && EconomyManager.getManager().isEnabled("Vault")) {
-            config.set("Main.Economy", "Vault");
-        } else if (config.getBoolean("Economy.Use Reserve Economy") && EconomyManager.getManager().isEnabled("Reserve")) {
-            config.set("Main.Economy", "Reserve");
-        } else if (config.getBoolean("Economy.Use Player Points Economy") && EconomyManager.getManager().isEnabled("PlayerPoints")) {
-            config.set("Main.Economy", "PlayerPoints");
+        if (CONFIG.getBoolean("Economy.Use Vault Economy") && EconomyManager.getManager().isEnabled("Vault")) {
+            CONFIG.set("Main.Economy", "Vault");
+        } else if (CONFIG.getBoolean("Economy.Use Reserve Economy") && EconomyManager.getManager().isEnabled("Reserve")) {
+            CONFIG.set("Main.Economy", "Reserve");
+        } else if (CONFIG.getBoolean("Economy.Use Player Points Economy") && EconomyManager.getManager().isEnabled("PlayerPoints")) {
+            CONFIG.set("Main.Economy", "PlayerPoints");
         }
 
-        config.saveChanges();
+        CONFIG.saveChanges();
     }
 }

src/main/java/com/songoda/epichoppers/tasks/HopTask.java

@@ -33,13 +33,8 @@ import java.util.concurrent.ThreadLocalRandom;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
-/**
- * Created by songoda on 3/14/2017.
- */
 public class HopTask extends BukkitRunnable {
-
-    // Hop to the bop to the be bop top.
-    private EpicHoppers plugin;
+    private final EpicHoppers plugin;
     private final int hopTicks;
 
     public HopTask(EpicHoppers plugin) {
@@ -50,22 +45,24 @@ public class HopTask extends BukkitRunnable {
 
     @Override
     public void run() {
-        for (final com.songoda.epichoppers.hopper.Hopper hopper : plugin.getHopperManager().getHoppers().values()) {
+        for (final com.songoda.epichoppers.hopper.Hopper hopper : this.plugin.getHopperManager().getHoppers().values()) {
 
             try {
-                // Get this hoppers location.
+                // Get this hopper's location.
                 Location location = hopper.getLocation();
 
                 // Skip if chunk is not loaded.
-                if (location.getWorld() == null || !location.getWorld().isChunkLoaded(location.getBlockX() >> 4, location.getBlockZ() >> 4))
+                if (location.getWorld() == null || !location.getWorld().isChunkLoaded(location.getBlockX() >> 4, location.getBlockZ() >> 4)) {
                     continue;
+                }
 
                 // Get Hopper Block.
                 Block block = location.getBlock();
 
                 // If block is not a hopper continue.
-                if (block.getType() != Material.HOPPER)
+                if (block.getType() != Material.HOPPER) {
                     continue;
+                }
 
                 // If hopper block is powered, update its redstone state and continue.
                 if (block.getBlockPower() > 0) {
@@ -73,11 +70,12 @@ public class HopTask extends BukkitRunnable {
                     continue;
                 }
 
-                if (!hopper.tryTick(this.hopTicks, true))
+                if (!hopper.tryTick(this.hopTicks, true)) {
                     continue;
+                }
 
                 // Amount to be moved.
-                BoostData boostData = plugin.getBoostManager().getBoost(hopper.getPlacedBy());
+                BoostData boostData = this.plugin.getBoostManager().getBoost(hopper.getPlacedBy());
                 int maxToMove = hopper.getLevel().getAmount() * (boostData == null ? 1 : boostData.getMultiplier());
 
                 // Get hopper state data.
@@ -99,8 +97,9 @@ public class HopTask extends BukkitRunnable {
 
                                 // Add banned materials to list.
                                 List<Material> materials = module.getBlockedItems(hopper);
-                                if (materials != null && !materials.isEmpty())
+                                if (materials != null && !materials.isEmpty()) {
                                     blockedMaterials.addAll(materials);
+                                }
                             } catch (Exception ex) {
                                 ex.printStackTrace();
                             }
@@ -124,16 +123,18 @@ public class HopTask extends BukkitRunnable {
                                     || (hopperCache.cacheChanged[i] && item.getAmount() - hopperCache.cacheAdded[i] < maxToMove)
                                     // skip if blocked or voidlisted
                                     || blockedMaterials.contains(item.getType())
-                                    || hopper.getFilter().getVoidList().stream().anyMatch(itemStack -> Methods.isSimilarMaterial(itemStack, item)))
+                                    || hopper.getFilter().getVoidList().stream().anyMatch(itemStack -> Methods.isSimilarMaterial(itemStack, item))) {
                         continue;
+                    }
 
                     doProcess = true;
                     break;
                 }
-                if (!doProcess)
+                if (!doProcess) {
                     continue;
+                }
 
-                CustomContainer container = plugin.getContainerManager().getCustomContainer(pointingLocation.getBlock());
+                CustomContainer container = this.plugin.getContainerManager().getCustomContainer(pointingLocation.getBlock());
                 if (container != null) {
                     for (int i = 0; i < 5; i++) {
                         final ItemStack item = hopperCache.cachedInventory[i];
@@ -165,10 +166,11 @@ public class HopTask extends BukkitRunnable {
     }
 
     private void debt(ItemStack item, int amountToMove, InventoryHolder currentHolder) {
-        if (item.getAmount() - amountToMove > 0)
+        if (item.getAmount() - amountToMove > 0) {
             item.setAmount(item.getAmount() - amountToMove);
-        else
+        } else {
             currentHolder.getInventory().removeItem(item);
+        }
     }
 
     private StorageContainerCache.Cache getFilterEndpoint(com.songoda.epichoppers.hopper.Hopper hopper) {
@@ -176,11 +178,14 @@ public class HopTask extends BukkitRunnable {
         Location endPoint = hopper.getFilter().getEndPoint();
 
         // Check for null.
-        if (endPoint == null) return null;
+        if (endPoint == null) {
+            return null;
+        }
 
         // Make sure chunk is loaded.
-        if (!endPoint.getWorld().isChunkLoaded(endPoint.getBlockX() >> 4, endPoint.getBlockZ() >> 4))
+        if (!endPoint.getWorld().isChunkLoaded(endPoint.getBlockX() >> 4, endPoint.getBlockZ() >> 4)) {
             return null;
+        }
 
         // Fetch Cache
         StorageContainerCache.Cache cache = StorageContainerCache.getCachedInventory(endPoint.getBlock());
@@ -202,7 +207,7 @@ public class HopTask extends BukkitRunnable {
         Collection<Entity> nearbyEntities = null;
         StorageContainerCache.Cache aboveCache = null;
 
-        CustomContainer container = plugin.getContainerManager().getCustomContainer(above);
+        CustomContainer container = this.plugin.getContainerManager().getCustomContainer(above);
         if ((container != null)
                 || (above.getType() != Material.AIR)
                 && (above.getType() != Material.HOPPER || HopperDirection.getDirection(above.getState().getRawData()) != HopperDirection.DOWN)
@@ -223,8 +228,9 @@ public class HopTask extends BukkitRunnable {
                 pullableSlots = IntStream.rangeClosed(0, contents.length - 1).toArray();
             } else {
                 if ((aboveInvHolder = this.getRandomInventoryHolderFromEntities(nearbyEntities)) == null
-                        || ((Minecart) aboveInvHolder).getLocation().getBlockY() + 1 == above.getY())
+                        || ((Minecart) aboveInvHolder).getLocation().getBlockY() + 1 == above.getY()) {
                     return;
+                }
                 if (aboveInvHolder instanceof StorageMinecart) {
                     pullableSlots = IntStream.rangeClosed(0, 26).toArray();
                 } else {
@@ -243,13 +249,15 @@ public class HopTask extends BukkitRunnable {
                 final ItemStack toMove = contents[i];
 
                 // If item is invalid, try the next slot.
-                if (toMove == null || toMove.getAmount() == 0)
+                if (toMove == null || toMove.getAmount() == 0) {
                     continue;
+                }
 
                 // if we're not moving the item that we're trying to craft, we need to verify that we're not trying to fill the last slot
                 // (filling every slot leaves no room for the crafter to function)
-                if (toCraft != null && !Methods.isSimilarMaterial(toMove, toCraft) && !Methods.canMoveReserved(hopperCache.cachedInventory, toMove))
+                if (toCraft != null && !Methods.isSimilarMaterial(toMove, toCraft) && !Methods.canMoveReserved(hopperCache.cachedInventory, toMove)) {
                     continue;
+                }
 
                 // respect whitelist/blacklist filters
                 if (toHopper.getFilter().getEndPoint() == null
@@ -285,9 +293,9 @@ public class HopTask extends BukkitRunnable {
                     if (aboveCache != null) {
                         aboveCache.removeItems(itemToMove);
                     } else {
-                        if (container != null)
+                        if (container != null) {
                             container.removeFromContainer(itemToMove, amountToMove);
-                        else {
+                        } else {
                             this.debt(itemToMove, amountToMove, aboveInvHolder);
                         }
                     }
@@ -309,9 +317,7 @@ public class HopTask extends BukkitRunnable {
         // Add container that the hopper is attached to physically.
         final Location pointingLocation = hopper.getLocation().add(hopperDirection.getX(), hopperDirection.getY(), hopperDirection.getZ());
         if (!linkedContainers.contains(pointingLocation)
-                && pointingLocation.getWorld().isChunkLoaded(
-                pointingLocation.getBlockX() >> 4,
-                pointingLocation.getBlockZ() >> 4)) {
+                && pointingLocation.getWorld().isChunkLoaded(pointingLocation.getBlockX() >> 4, pointingLocation.getBlockZ() >> 4)) {
             switch (pointingLocation.getBlock().getType().name()) {
                 case "AIR":
                 case "RAILS":
@@ -330,8 +336,9 @@ public class HopTask extends BukkitRunnable {
         for (Location targetLocation : linkedContainers) {
 
             // Don't check if it's not in a loaded chunk
-            if (!targetLocation.getWorld().isChunkLoaded(targetLocation.getBlockX() >> 4, targetLocation.getBlockZ() >> 4))
+            if (!targetLocation.getWorld().isChunkLoaded(targetLocation.getBlockX() >> 4, targetLocation.getBlockZ() >> 4)) {
                 continue;
+            }
 
             // special case for ender chests
             final Block targetBlock = targetLocation.getBlock();
@@ -343,8 +350,9 @@ public class HopTask extends BukkitRunnable {
                     StorageContainerCache.Cache cache = new StorageContainerCache.Cache(targetBlock.getType(), destinationInventory.getContents());
                     if (tryPush(hopper, hopperCache, cache, filterCache, maxToMove, blockedMaterials)) {
                         // update inventory and exit
-                        if (cache.isDirty())
+                        if (cache.isDirty()) {
                             destinationInventory.setContents(cache.cachedInventory);
+                        }
                         return;
                     }
                 }
@@ -352,7 +360,7 @@ public class HopTask extends BukkitRunnable {
                 continue;
             }
 
-            CustomContainer container = plugin.getContainerManager().getCustomContainer(targetLocation.getBlock());
+            CustomContainer container = this.plugin.getContainerManager().getCustomContainer(targetLocation.getBlock());
             if (container != null && tryPushCustomContainer(hopper, hopperCache, container, filterCache, maxToMove, blockedMaterials)) {
                 return;
             }
@@ -366,8 +374,9 @@ public class HopTask extends BukkitRunnable {
             }
 
             // Now attempt to push items into this container and exit on success
-            if (tryPush(hopper, hopperCache, targetCache, filterCache, maxToMove, blockedMaterials))
+            if (tryPush(hopper, hopperCache, targetCache, filterCache, maxToMove, blockedMaterials)) {
                 return;
+            }
         }
 
         // if we've gotten this far, check if we can push into a minecart
@@ -377,8 +386,9 @@ public class HopTask extends BukkitRunnable {
                     .map(InventoryHolder.class::cast).collect(Collectors.toSet())) {
                 StorageContainerCache.Cache cache = new StorageContainerCache.Cache(Material.CHEST, minecartInventory.getInventory().getContents());
                 if (tryPush(hopper, hopperCache, cache, filterCache, maxToMove, blockedMaterials)) {
-                    if (cache.isDirty())
+                    if (cache.isDirty()) {
                         minecartInventory.getInventory().setContents(cache.cachedInventory);
+                    }
                     return;
                 }
             }
@@ -401,8 +411,9 @@ public class HopTask extends BukkitRunnable {
                             || (hopperCache.cacheChanged[i] && item.getAmount() - hopperCache.cacheAdded[i] < maxToMove)
                             // skip if blocked or voidlisted
                             || blockedMaterials.contains(item.getType())
-                            || hopper.getFilter().getVoidList().stream().anyMatch(itemStack -> Methods.isSimilarMaterial(itemStack, item)))
+                            || hopper.getFilter().getVoidList().stream().anyMatch(itemStack -> Methods.isSimilarMaterial(itemStack, item))) {
                 continue;
+            }
 
             // Create item that will be moved.
             ItemStack itemToMove = item.clone();
@@ -449,8 +460,9 @@ public class HopTask extends BukkitRunnable {
                             || (hopperCache.cacheChanged[i] && item.getAmount() - hopperCache.cacheAdded[i] < maxToMove)
                             // skip if blocked or voidlisted
                             || blockedMaterials.contains(item.getType())
-                            || hopper.getFilter().getVoidList().stream().anyMatch(itemStack -> Methods.isSimilarMaterial(itemStack, item)))
+                            || hopper.getFilter().getVoidList().stream().anyMatch(itemStack -> Methods.isSimilarMaterial(itemStack, item))) {
                 continue;
+            }
 
             // Create item that will be moved.
             ItemStack itemToMove = item.clone();
@@ -506,8 +518,9 @@ public class HopTask extends BukkitRunnable {
      * @return A set of valid pullable slots
      */
     private int[] getPullableSlots(Material material, int contentsLength) {
-        if (material.name().contains("SHULKER_BOX"))
+        if (material.name().contains("SHULKER_BOX")) {
             return IntStream.rangeClosed(0, 26).toArray();
+        }
 
         switch (material.name()) {
             case "BARREL":
@@ -542,10 +555,12 @@ public class HopTask extends BukkitRunnable {
         List<InventoryHolder> inventoryHolders = new ArrayList<>();
         entities.stream().filter(e -> e.getType() == EntityType.MINECART_CHEST || e.getType() == EntityType.MINECART_HOPPER)
                 .forEach(e -> inventoryHolders.add((InventoryHolder) e));
-        if (inventoryHolders.isEmpty())
+        if (inventoryHolders.isEmpty()) {
             return null;
-        if (inventoryHolders.size() == 1)
+        }
+        if (inventoryHolders.size() == 1) {
             return inventoryHolders.get(0);
+        }
         return inventoryHolders.get(ThreadLocalRandom.current().nextInt(inventoryHolders.size()));
     }
-}
+}

src/main/java/com/songoda/epichoppers/utils/CostType.java

@@ -1,7 +1,5 @@
 package com.songoda.epichoppers.utils;
 
 public enum CostType {
-
     ECONOMY, EXPERIENCE
-
-}
+}

src/main/java/com/songoda/epichoppers/utils/HopperDirection.java

@@ -4,7 +4,6 @@ import org.bukkit.Location;
 import org.bukkit.block.BlockFace;
 
 public enum HopperDirection {
-
     DOWN(0, 8, 0, -1, 0),
     NORTH(2, 10, 0, 0, -1),
     SOUTH(3, 11, 0, 0, 1),
@@ -28,9 +27,11 @@ public enum HopperDirection {
     }
 
     public static HopperDirection getDirection(int value) {
-        for (HopperDirection hopperDirection : HopperDirection.values())
-            if (hopperDirection.getPowered() == value || hopperDirection.getUnpowered() == value)
+        for (HopperDirection hopperDirection : HopperDirection.values()) {
+            if (hopperDirection.getPowered() == value || hopperDirection.getUnpowered() == value) {
                 return hopperDirection;
+            }
+        }
         return null;
     }
 
@@ -54,22 +55,22 @@ public enum HopperDirection {
     }
 
     public int getX() {
-        return x;
+        return this.x;
     }
 
     public int getY() {
-        return y;
+        return this.y;
     }
 
     public int getZ() {
-        return z;
+        return this.z;
     }
 
     public int getUnpowered() {
-        return unpowered;
+        return this.unpowered;
     }
 
     public int getPowered() {
-        return powered;
+        return this.powered;
     }
-}
+}

src/main/java/com/songoda/epichoppers/utils/Methods.java

@@ -10,14 +10,7 @@ import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
 
-import java.text.DecimalFormat;
-import java.util.concurrent.TimeUnit;
-
-/**
- * Created by songoda on 2/24/2017.
- */
 public class Methods {
-
     public static boolean isSimilarMaterial(ItemStack is1, ItemStack is2) {
         if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13) ||
                 is1.getDurability() == Short.MAX_VALUE || is2.getDurability() == Short.MAX_VALUE) {
@@ -29,7 +22,9 @@ public class Methods {
     }
 
     public static boolean canMove(Inventory inventory, ItemStack item) {
-        if (inventory.firstEmpty() != -1) return true;
+        if (inventory.firstEmpty() != -1) {
+            return true;
+        }
 
         final ItemMeta itemMeta = item.getItemMeta();
         for (ItemStack stack : inventory) {
@@ -44,7 +39,9 @@ public class Methods {
     }
 
     public static boolean canMoveReserved(Inventory inventory, ItemStack item) {
-        if (inventory.firstEmpty() != inventory.getSize() - 1) return true;
+        if (inventory.firstEmpty() != inventory.getSize() - 1) {
+            return true;
+        }
 
         final ItemMeta itemMeta = item.getItemMeta();
         final ItemStack[] contents = inventory.getContents();
@@ -64,8 +61,9 @@ public class Methods {
         final ItemMeta itemMeta = item.getItemMeta();
         for (int i = 0; i < contents.length - 2; i++) {
             final ItemStack stack = contents[i];
-            if (stack == null || stack.getAmount() == 0)
+            if (stack == null || stack.getAmount() == 0) {
                 return true;
+            }
             final ItemMeta stackMeta;
             if (isSimilarMaterial(stack, item) && (stack.getAmount() + item.getAmount()) < stack.getMaxStackSize()
                     && ((itemMeta == null) == ((stackMeta = stack.getItemMeta()) == null))
@@ -77,23 +75,24 @@ public class Methods {
     }
 
     public static String formatName(int level) {
-        EpicHoppers instance = EpicHoppers.getInstance();
-        String name = instance.getLocale().getMessage("general.nametag.nameformat")
-                .processPlaceholder("level", level).getMessage();
+        EpicHoppers instance = EpicHoppers.getPlugin(EpicHoppers.class);
+        String name = instance.getLocale()
+                .getMessage("general.nametag.nameformat")
+                .processPlaceholder("level", level)
+                .getMessage();
 
 
         return TextUtils.formatText(name);
     }
 
     public static void doParticles(Entity entity, Location location) {
-        EpicHoppers instance = EpicHoppers.getInstance();
+        EpicHoppers instance = EpicHoppers.getPlugin(EpicHoppers.class);
         location.setX(location.getX() + .5);
         location.setY(location.getY() + .5);
         location.setZ(location.getZ() + .5);
         entity.getWorld().spawnParticle(org.bukkit.Particle.valueOf(instance.getConfig().getString("Main.Upgrade Particle Type")), location, 200, .5, .5, .5);
     }
 
-
     /**
      * Serializes the location specified.
      *
@@ -101,8 +100,9 @@ public class Methods {
      * @return The serialized data.
      */
     public static String serializeLocation(Location location) {
-        if (location == null || location.getWorld() == null)
+        if (location == null || location.getWorld() == null) {
             return "";
+        }
         String w = location.getWorld().getName();
         double x = location.getX();
         double y = location.getY();
@@ -111,84 +111,4 @@ public class Methods {
         str = str.replace(".0", "").replace(".", "/");
         return str;
     }
-
-    /**
-     * Makes the specified Unix Epoch time human readable as per the format settings in the Arconix config.
-     *
-     * @param time The time to convert.
-     * @return A human readable string representing to specified time.
-     */
-    public static String makeReadable(Long time) {
-        if (time == null)
-            return "";
-
-        StringBuilder sb = new StringBuilder();
-
-        long days = TimeUnit.MILLISECONDS.toDays(time);
-        long hours = TimeUnit.MILLISECONDS.toHours(time) - TimeUnit.DAYS.toHours(TimeUnit.MILLISECONDS.toDays(time));
-        long minutes = TimeUnit.MILLISECONDS.toMinutes(time) - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(time));
-        long seconds = TimeUnit.MILLISECONDS.toSeconds(time) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(time));
-
-        if (days != 0L)
-            sb.append(" ").append(days).append("d");
-        if (hours != 0L)
-            sb.append(" ").append(hours).append("h");
-        if (minutes != 0L)
-            sb.append(" ").append(minutes).append("m");
-        if (seconds != 0L)
-            sb.append(" ").append(seconds).append("s");
-        return sb.toString().trim();
-    }
-
-    public static long parseTime(String input) {
-        long result = 0;
-        StringBuilder number = new StringBuilder();
-        for (int i = 0; i < input.length(); i++) {
-            char c = input.charAt(i);
-            if (Character.isDigit(c)) {
-                number.append(c);
-            } else if (Character.isLetter(c) && (number.length() > 0)) {
-                result += convert(Integer.parseInt(number.toString()), c);
-                number = new StringBuilder();
-            }
-        }
-        return result;
-    }
-
-    private static long convert(long value, char unit) {
-        switch (unit) {
-            case 'd':
-                return value * 1000 * 60 * 60 * 24;
-            case 'h':
-                return value * 1000 * 60 * 60;
-            case 'm':
-                return value * 1000 * 60;
-            case 's':
-                return value * 1000;
-            default:
-                return 0;
-        }
-    }
-
-    /**
-     * Formats the specified double into the Economy format specified in the Arconix config.
-     *
-     * @param amt The double to format.
-     * @return The economy formatted double.
-     */
-    public static String formatEconomy(double amt) {
-        DecimalFormat formatter = new DecimalFormat(amt == Math.ceil(amt) ? "#,###" : "#,###.00");
-        return formatter.format(amt);
-    }
-
-    public static boolean isInt(String number) {
-        if (number == null || number.equals(""))
-            return false;
-        try {
-            Integer.parseInt(number);
-        } catch (NumberFormatException e) {
-            return false;
-        }
-        return true;
-    }
 }

src/main/java/com/songoda/epichoppers/utils/StorageContainerCache.java

@@ -21,25 +21,24 @@ import java.util.Map;
  * containers in large batches
  */
 public class StorageContainerCache {
-
-    private static final Map<Block, Cache> inventoryCache = new HashMap<>();
+    private static final Map<Block, Cache> INVENTORY_CACHE = new HashMap<>();
 
     // need to get the topmost inventory for a double chest, and save as that block
-    public static Cache getCachedInventory(Block b) {
-        Cache cache = inventoryCache.get(b);
+    public static Cache getCachedInventory(Block block) {
+        Cache cache = INVENTORY_CACHE.get(block);
         if (cache == null) {
-            Material type = b.getType();
+            Material type = block.getType();
             if (type == Material.CHEST || type == Material.TRAPPED_CHEST) {
-                Block b2 = findAdjacentDoubleChest(b);
-                //System.out.println("Adjacent to " + b + " = " + b2);
-                if (b2 != null && (cache = inventoryCache.get(b2)) != null) {
+                Block b2 = findAdjacentDoubleChest(block);
+                //System.out.println("Adjacent to " + block + " = " + b2);
+                if (b2 != null && (cache = INVENTORY_CACHE.get(b2)) != null) {
                     return cache;
                 }
             }
-            BlockState blockState = b.getState();
+            BlockState blockState = block.getState();
             if (blockState instanceof InventoryHolder) {
-                //System.out.println("Load " + b.getLocation());
-                inventoryCache.put(b, cache = new Cache(b, ((InventoryHolder) blockState).getInventory().getContents()));
+                //System.out.println("Load " + block.getLocation());
+                INVENTORY_CACHE.put(block, cache = new Cache(block, ((InventoryHolder) blockState).getInventory().getContents()));
             }
         }
         return cache;
@@ -47,30 +46,27 @@ public class StorageContainerCache {
 
     /**
      * Look for a double chest adjacent to a chest
-     *
-     * @param block
-     * @return
      */
     public static Block findAdjacentDoubleChest(Block block) {
         if (ServerVersion.isServerVersionAtLeast(ServerVersion.V1_13)) {
-            final BlockData d = block.getBlockData();
-            if (d instanceof Chest) {
-                final Chest c = (Chest) d;
-                if (c.getType() != Chest.Type.SINGLE) {
+            final BlockData blockData = block.getBlockData();
+            if (blockData instanceof Chest) {
+                final Chest chest = (Chest) blockData;
+                if (chest.getType() != Chest.Type.SINGLE) {
                     // this is a double chest - check the other chest for registration data
                     Block other = null;
-                    switch (c.getFacing()) {
+                    switch (chest.getFacing()) {
                         case SOUTH:
-                            other = block.getRelative(c.getType() != Chest.Type.RIGHT ? BlockFace.WEST : BlockFace.EAST);
+                            other = block.getRelative(chest.getType() != Chest.Type.RIGHT ? BlockFace.WEST : BlockFace.EAST);
                             break;
                         case NORTH:
-                            other = block.getRelative(c.getType() != Chest.Type.RIGHT ? BlockFace.EAST : BlockFace.WEST);
+                            other = block.getRelative(chest.getType() != Chest.Type.RIGHT ? BlockFace.EAST : BlockFace.WEST);
                             break;
                         case EAST:
-                            other = block.getRelative(c.getType() != Chest.Type.RIGHT ? BlockFace.SOUTH : BlockFace.NORTH);
+                            other = block.getRelative(chest.getType() != Chest.Type.RIGHT ? BlockFace.SOUTH : BlockFace.NORTH);
                             break;
                         case WEST:
-                            other = block.getRelative(c.getType() != Chest.Type.RIGHT ? BlockFace.NORTH : BlockFace.SOUTH);
+                            other = block.getRelative(chest.getType() != Chest.Type.RIGHT ? BlockFace.NORTH : BlockFace.SOUTH);
                             break;
                         default:
                             break;
@@ -84,7 +80,7 @@ public class StorageContainerCache {
         } else {
             // legacy check
             Material material = block.getType();
-            BlockFace[] faces = new BlockFace[] {BlockFace.NORTH, BlockFace.SOUTH, BlockFace.EAST, BlockFace.WEST};
+            BlockFace[] faces = new BlockFace[]{BlockFace.NORTH, BlockFace.SOUTH, BlockFace.EAST, BlockFace.WEST};
             for (BlockFace face : faces) {
                 Block adjacentBlock = block.getRelative(face);
 
@@ -97,7 +93,7 @@ public class StorageContainerCache {
     }
 
     public static void update() {
-        inventoryCache.entrySet().stream()
+        INVENTORY_CACHE.entrySet().stream()
                 .filter(e -> e.getValue().dirty)
                 .forEach(e -> {
                     //System.out.println("Update " + e.getKey().getLocation());
@@ -115,11 +111,10 @@ public class StorageContainerCache {
 
                     NmsManager.getWorld().updateAdjacentComparators(e.getKey());
                 });
-        inventoryCache.clear();
+        INVENTORY_CACHE.clear();
     }
 
     public static class Cache {
-
         public final Material type;
         public final Block block;
         public ItemStack[] cachedInventory;
@@ -135,9 +130,9 @@ public class StorageContainerCache {
             this.cacheAdded = new int[cachedInventory.length];
         }
 
-        public Cache(Block b, ItemStack[] cachedInventory) {
-            this.block = b;
-            this.type = b.getType();
+        public Cache(Block block, ItemStack[] cachedInventory) {
+            this.block = block;
+            this.type = block.getType();
             this.cachedInventory = cachedInventory;
             this.cacheChanged = new boolean[cachedInventory.length];
             this.cacheAdded = new int[cachedInventory.length];
@@ -152,50 +147,50 @@ public class StorageContainerCache {
         }
 
         public void setContents(ItemStack[] items) {
-            if (cachedInventory == null || items.length == cachedInventory.length) {
-                cachedInventory = items;
-                for (int i = 0; i < cachedInventory.length; i++) {
-                    cacheChanged[i] = true;
+            if (this.cachedInventory == null || items.length == this.cachedInventory.length) {
+                this.cachedInventory = items;
+                for (int i = 0; i < this.cachedInventory.length; i++) {
+                    this.cacheChanged[i] = true;
                 }
-                dirty = true;
+                this.dirty = true;
             }
         }
 
         public void setItem(int item, ItemStack itemStack) {
-            if (cachedInventory != null) {
-                cachedInventory[item] = itemStack;
-                cacheChanged[item] = true;
-                dirty = true;
+            if (this.cachedInventory != null) {
+                this.cachedInventory[item] = itemStack;
+                this.cacheChanged[item] = true;
+                this.dirty = true;
             }
         }
 
         public void removeItem(int item) {
-            if (cachedInventory != null) {
-                cachedInventory[item] = null;
-                cacheChanged[item] = true;
-                dirty = true;
+            if (this.cachedInventory != null) {
+                this.cachedInventory[item] = null;
+                this.cacheChanged[item] = true;
+                this.dirty = true;
             }
         }
 
         public void removeItems(ItemStack item) {
-            if (cachedInventory != null && item != null) {
+            if (this.cachedInventory != null && item != null) {
                 int toRemove = item.getAmount();
-                for (int i = 0; toRemove > 0 && i < cachedInventory.length; i++) {
-                    final ItemStack cacheItem = cachedInventory[i];
+                for (int i = 0; toRemove > 0 && i < this.cachedInventory.length; i++) {
+                    final ItemStack cacheItem = this.cachedInventory[i];
                     if (cacheItem != null && cacheItem.getAmount() != 0 && item.isSimilar(cacheItem)) {
                         int have = cacheItem.getAmount();
                         if (have > toRemove) {
-                            cachedInventory[i].setAmount(have - toRemove);
-                            cacheChanged[i] = true;
+                            this.cachedInventory[i].setAmount(have - toRemove);
+                            this.cacheChanged[i] = true;
                             toRemove = 0;
                         } else {
-                            cachedInventory[i] = null;
-                            cacheChanged[i] = true;
+                            this.cachedInventory[i] = null;
+                            this.cacheChanged[i] = true;
                             toRemove -= have;
                         }
                     }
                 }
-                dirty = dirty | (toRemove != item.getAmount());
+                this.dirty = this.dirty | (toRemove != item.getAmount());
             }
         }
 
@@ -207,37 +202,37 @@ public class StorageContainerCache {
          * @return how many items were added
          */
         public int addAny(ItemStack item, int amountToAdd) {
-
             // Don't transfer shulker boxes into other shulker boxes, that's a bad idea.
-            if (type.name().contains("SHULKER_BOX") && item.getType().name().contains("SHULKER_BOX"))
+            if (this.type.name().contains("SHULKER_BOX") && item.getType().name().contains("SHULKER_BOX")) {
                 return 0;
+            }
 
             int totalAdded = 0;
-            if (cachedInventory != null && item != null) {
+            if (this.cachedInventory != null && item != null) {
                 final int maxStack = item.getMaxStackSize();
-                for (int i = 0; amountToAdd > 0 && i < cachedInventory.length; i++) {
-                    final ItemStack cacheItem = cachedInventory[i];
+                for (int i = 0; amountToAdd > 0 && i < this.cachedInventory.length; i++) {
+                    final ItemStack cacheItem = this.cachedInventory[i];
                     if (cacheItem == null || cacheItem.getAmount() == 0) {
                         // free slot!
                         int toAdd = Math.min(maxStack, amountToAdd);
-                        cachedInventory[i] = item.clone();
-                        cachedInventory[i].setAmount(toAdd);
-                        cacheChanged[i] = true;
-                        cacheAdded[i] = toAdd;
+                        this.cachedInventory[i] = item.clone();
+                        this.cachedInventory[i].setAmount(toAdd);
+                        this.cacheChanged[i] = true;
+                        this.cacheAdded[i] = toAdd;
                         totalAdded += toAdd;
                         amountToAdd -= toAdd;
                     } else if (maxStack > cacheItem.getAmount() && item.isSimilar(cacheItem)) {
                         // free space!
                         int toAdd = Math.min(maxStack - cacheItem.getAmount(), amountToAdd);
-                        cachedInventory[i].setAmount(toAdd + cacheItem.getAmount());
-                        cacheChanged[i] = true;
-                        cacheAdded[i] += toAdd;
+                        this.cachedInventory[i].setAmount(toAdd + cacheItem.getAmount());
+                        this.cacheChanged[i] = true;
+                        this.cacheAdded[i] += toAdd;
                         totalAdded += toAdd;
                         amountToAdd -= toAdd;
                     }
                 }
                 if (totalAdded != 0) {
-                    dirty = true;
+                    this.dirty = true;
                 }
             }
             return totalAdded;
@@ -250,12 +245,14 @@ public class StorageContainerCache {
          * @return true if the item was added
          */
         public boolean addItem(ItemStack item) {
-            if (cachedInventory == null || item == null || item.getAmount() <= 0)
+            if (this.cachedInventory == null || item == null || item.getAmount() <= 0) {
                 return false;
+            }
 
             // Don't transfer shulker boxes into other shulker boxes, that's a bad idea.
-            if (type.name().contains("SHULKER_BOX") && item.getType().name().contains("SHULKER_BOX"))
+            if (this.type.name().contains("SHULKER_BOX") && item.getType().name().contains("SHULKER_BOX")) {
                 return false;
+            }
 
             // grab the amount to move and the max item stack size
             int toAdd = item.getAmount();
@@ -263,7 +260,7 @@ public class StorageContainerCache {
             boolean[] check = null;
 
             // some destination containers have special conditions
-            switch (type.name()) {
+            switch (this.type.name()) {
                 case "BREWING_STAND": {
 
                     // first compile a list of what slots to check
@@ -274,10 +271,11 @@ public class StorageContainerCache {
                         check[0] = check[1] = check[2] = true;
                     }
                     // fuel in 5th position, input in 4th
-                    if (item.getType() == Material.BLAZE_POWDER)
+                    if (item.getType() == Material.BLAZE_POWDER) {
                         check[4] = true;
-                    else if (CompatibleMaterial.getMaterial(item).isBrewingStandIngredient())
+                    } else if (CompatibleMaterial.getMaterial(item).isBrewingStandIngredient()) {
                         check[3] = true;
+                    }
 
                     break;
                 }
@@ -290,10 +288,11 @@ public class StorageContainerCache {
 
                     boolean isFuel = !item.getType().name().contains("LOG") && CompatibleMaterial.getMaterial(item.getType()).isFuel();
                     // fuel is 2nd slot, input is first
-                    if (isFuel)
+                    if (isFuel) {
                         check[1] = true;
-                    else
+                    } else {
                         check[0] = true;
+                    }
 
                     break;
                 }
@@ -303,15 +302,16 @@ public class StorageContainerCache {
 
             // we can reduce calls to ItemStack.isSimilar() by caching what cells to look at
             if (check == null) {
-                check = new boolean[cachedInventory.length];
-                for (int i = 0; toAdd > 0 && i < check.length; i++)
+                check = new boolean[this.cachedInventory.length];
+                for (int i = 0; toAdd > 0 && i < check.length; i++) {
                     check[i] = true;
+                }
             }
 
             // first verify that we can add this item
-            for (int i = 0; toAdd > 0 && i < cachedInventory.length; i++) {
+            for (int i = 0; toAdd > 0 && i < this.cachedInventory.length; i++) {
                 if (check[i]) {
-                    final ItemStack cacheItem = cachedInventory[i];
+                    final ItemStack cacheItem = this.cachedInventory[i];
                     if (cacheItem == null || cacheItem.getAmount() == 0) {
                         // free slot!
                         toAdd -= Math.min(maxStack, toAdd);
@@ -320,36 +320,38 @@ public class StorageContainerCache {
                         // free space!
                         toAdd -= Math.min(maxStack - cacheItem.getAmount(), toAdd);
                         check[i] = true;
-                    } else
+                    } else {
                         check[i] = false;
+                    }
                 }
             }
             if (toAdd <= 0) {
                 // all good to add!
                 toAdd = item.getAmount();
-                for (int i = 0; toAdd > 0 && i < cachedInventory.length; i++) {
-                    if (!check[i])
+                for (int i = 0; toAdd > 0 && i < this.cachedInventory.length; i++) {
+                    if (!check[i]) {
                         continue;
-                    final ItemStack cacheItem = cachedInventory[i];
+                    }
+                    final ItemStack cacheItem = this.cachedInventory[i];
                     if (cacheItem == null || cacheItem.getAmount() == 0) {
                         // free slot!
                         int adding = Math.min(maxStack, toAdd);
-                        cachedInventory[i] = item.clone();
-                        cachedInventory[i].setAmount(adding);
-                        cacheChanged[i] = true;
-                        cacheAdded[i] = adding;
+                        this.cachedInventory[i] = item.clone();
+                        this.cachedInventory[i].setAmount(adding);
+                        this.cacheChanged[i] = true;
+                        this.cacheAdded[i] = adding;
                         toAdd -= adding;
                     } else if (maxStack > cacheItem.getAmount()) {
                         // free space!
                         // (no need to check item.isSimilar(cacheItem), since we have that cached in check[])
                         int adding = Math.min(maxStack - cacheItem.getAmount(), toAdd);
-                        cachedInventory[i].setAmount(adding + cacheItem.getAmount());
-                        cacheChanged[i] = true;
-                        cacheAdded[i] += adding;
+                        this.cachedInventory[i].setAmount(adding + cacheItem.getAmount());
+                        this.cacheChanged[i] = true;
+                        this.cacheAdded[i] += adding;
                         toAdd -= adding;
                     }
                 }
-                dirty = true;
+                this.dirty = true;
                 return true;
             }
             return false;