Cleanup

src/main/java/net/minestom/server/MinecraftServer.java

@@ -119,6 +119,8 @@ public final class MinecraftServer {
 
     private static ExtensionManager extensionManager;
 
+    private static final GlobalEventHandler GLOBAL_EVENT_HANDLER = new GlobalEventHandler();
+
     private static UpdateManager updateManager;
     private static MinecraftServer minecraftServer;
 
@@ -134,7 +136,6 @@ public final class MinecraftServer {
     private static ResponseDataConsumer responseDataConsumer;
     private static String brandName = "Minestom";
     private static Difficulty difficulty = Difficulty.NORMAL;
-    private static GlobalEventHandler globalEventHandler = new GlobalEventHandler();
     private static LootTableManager lootTableManager;
     private static TagManager tagManager;
 
@@ -293,7 +294,7 @@ public final class MinecraftServer {
      */
     @NotNull
     public static GlobalEventHandler getGlobalEventHandler() {
-        return globalEventHandler;
+        return GLOBAL_EVENT_HANDLER;
     }
 
     /**

src/main/java/net/minestom/server/command/builder/CommandDispatcher.java

@@ -38,11 +38,16 @@ public class CommandDispatcher {
     }
 
     public void unregister(@NotNull Command command) {
-        commandMap.remove(command.getName().toLowerCase());
-        for (String alias : command.getAliases()) {
-            this.commandMap.remove(alias.toLowerCase());
+        this.commandMap.remove(command.getName().toLowerCase());
+
+        final String[] aliases = command.getAliases();
+        if (aliases != null) {
+            for (String alias : aliases) {
+                this.commandMap.remove(alias.toLowerCase());
+            }
         }
-        commands.remove(command);
+
+        this.commands.remove(command);
     }
 
     /**

src/main/java/net/minestom/server/command/builder/arguments/ArgumentDynamicWord.java

@@ -15,7 +15,7 @@ public class ArgumentDynamicWord extends Argument<String> {
     public static final int SPACE_ERROR = 1;
     public static final int RESTRICTION_ERROR = 2;
 
-    private SuggestionType suggestionType;
+    private final SuggestionType suggestionType;
 
     private StringValidator dynamicRestriction;
 

src/main/java/net/minestom/server/command/builder/arguments/minecraft/registry/ArgumentBlockState.java

@@ -11,7 +11,7 @@ public class ArgumentBlockState extends ArgumentRegistry<Block> {
     }
 
     @Override
-    public Block getRegistry(String value) {
+    public Block getRegistry(@NotNull String value) {
         return Registries.getBlock(value);
     }
 }

src/main/java/net/minestom/server/command/builder/arguments/minecraft/registry/ArgumentEnchantment.java

@@ -2,6 +2,7 @@ package net.minestom.server.command.builder.arguments.minecraft.registry;
 
 import net.minestom.server.item.Enchantment;
 import net.minestom.server.registry.Registries;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Represents an argument giving an {@link Enchantment}.
@@ -13,7 +14,7 @@ public class ArgumentEnchantment extends ArgumentRegistry<Enchantment> {
     }
 
     @Override
-    public Enchantment getRegistry(String value) {
+    public Enchantment getRegistry(@NotNull String value) {
         return Registries.getEnchantment(value);
     }
 }

src/main/java/net/minestom/server/command/builder/arguments/minecraft/registry/ArgumentEntityType.java

@@ -2,6 +2,7 @@ package net.minestom.server.command.builder.arguments.minecraft.registry;
 
 import net.minestom.server.entity.EntityType;
 import net.minestom.server.registry.Registries;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Represents an argument giving an {@link EntityType}.
@@ -13,7 +14,7 @@ public class ArgumentEntityType extends ArgumentRegistry<EntityType> {
     }
 
     @Override
-    public EntityType getRegistry(String value) {
+    public EntityType getRegistry(@NotNull String value) {
         return Registries.getEntityType(value);
     }
 }

src/main/java/net/minestom/server/command/builder/arguments/minecraft/registry/ArgumentParticle.java

@@ -2,6 +2,7 @@ package net.minestom.server.command.builder.arguments.minecraft.registry;
 
 import net.minestom.server.particle.Particle;
 import net.minestom.server.registry.Registries;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Represents an argument giving a {@link Particle}.
@@ -13,7 +14,7 @@ public class ArgumentParticle extends ArgumentRegistry<Particle> {
     }
 
     @Override
-    public Particle getRegistry(String value) {
+    public Particle getRegistry(@NotNull String value) {
         return Registries.getParticle(value);
     }
 }

src/main/java/net/minestom/server/command/builder/arguments/minecraft/registry/ArgumentPotionEffect.java

@@ -2,6 +2,7 @@ package net.minestom.server.command.builder.arguments.minecraft.registry;
 
 import net.minestom.server.potion.PotionEffect;
 import net.minestom.server.registry.Registries;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Represents an argument giving a {@link PotionEffect}.
@@ -13,7 +14,7 @@ public class ArgumentPotionEffect extends ArgumentRegistry<PotionEffect> {
     }
 
     @Override
-    public PotionEffect getRegistry(String value) {
+    public PotionEffect getRegistry(@NotNull String value) {
         return Registries.getPotionEffect(value);
     }
 }

src/main/java/net/minestom/server/data/Data.java

@@ -127,7 +127,7 @@ public abstract class Data implements PublicCloneable<Data> {
             return (Data) super.clone();
         } catch (CloneNotSupportedException e) {
             e.printStackTrace();
-            return null;
+            throw new IllegalStateException("Weird thing happened");
         }
     }
 }

src/main/java/net/minestom/server/entity/Entity.java

@@ -70,7 +70,7 @@ public abstract class Entity implements Viewable, EventHandler, DataContainer, P
     protected static final byte METADATA_POSE = 18;
 
     protected Instance instance;
-    protected Position position;
+    protected final Position position;
     protected float lastX, lastY, lastZ;
     protected float cacheX, cacheY, cacheZ; // Used to synchronize with #getPosition
     protected float lastYaw, lastPitch;

src/main/java/net/minestom/server/extensions/ExtensionDependencyResolver.java

@@ -18,10 +18,10 @@ import java.util.stream.Collectors;
  */
 public class ExtensionDependencyResolver implements DependencyResolver {
 
-    private Map<String, DiscoveredExtension> extensionMap = new HashMap<>();
+    private final Map<String, DiscoveredExtension> extensionMap = new HashMap<>();
 
-    public ExtensionDependencyResolver(List<DiscoveredExtension> extensions) {
-        for(DiscoveredExtension ext : extensions) {
+    public ExtensionDependencyResolver(@NotNull List<DiscoveredExtension> extensions) {
+        for (DiscoveredExtension ext : extensions) {
             extensionMap.put(ext.getName(), ext);
         }
     }
@@ -29,7 +29,7 @@ public class ExtensionDependencyResolver implements DependencyResolver {
     @NotNull
     @Override
     public ResolvedDependency resolve(@NotNull String extensionName, @NotNull File file) throws UnresolvedDependencyException {
-        if(extensionMap.containsKey(extensionName)) {
+        if (extensionMap.containsKey(extensionName)) {
             DiscoveredExtension ext = extensionMap.get(extensionName);
             // convert extension URLs to subdependencies
             // FIXME: this is not a deep conversion, this might create an issue in this scenario with different classloaders:
@@ -38,17 +38,20 @@ public class ExtensionDependencyResolver implements DependencyResolver {
             // When loading B, with no deep conversion, Ext will not be added to the list of dependencies (because it is not a direct dependency)
             // But when trying to call/access code from extension A, the parts dependent on Ext won't be inside B's dependencies, triggering a ClassNotFoundException
             List<ResolvedDependency> deps = new LinkedList<>();
-            for(URL u : ext.files) {
+            for (URL u : ext.files) {
                 deps.add(new ResolvedDependency(u.toExternalForm(), u.toExternalForm(), "", u, new LinkedList<>()));
             }
             return new ResolvedDependency(ext.getName(), ext.getName(), ext.getVersion(), ext.files.get(0), deps);
         }
-        throw new UnresolvedDependencyException("No extension named "+extensionName);
+        throw new UnresolvedDependencyException("No extension named " + extensionName);
     }
 
     @Override
     public String toString() {
-        String list = extensionMap.values().stream().map(entry -> entry.getName()).collect(Collectors.joining(", "));
+        String list = extensionMap.values()
+                .stream()
+                .map(DiscoveredExtension::getName)
+                .collect(Collectors.joining(", "));
         return "ExtensionDependencyResolver[" + list + "]";
     }
 }

src/main/java/net/minestom/server/extensions/ExtensionManager.java

@@ -468,7 +468,11 @@ public class ExtensionManager {
                 }
             } catch (Exception e) {
                 e.printStackTrace();
-                LOGGER.error("Failed to load code modifier for extension in files: " + extension.files.stream().map(u -> u.toExternalForm()).collect(Collectors.joining(", ")), e);
+                LOGGER.error("Failed to load code modifier for extension in files: " +
+                        extension.files
+                                .stream()
+                                .map(URL::toExternalForm)
+                                .collect(Collectors.joining(", ")), e);
             }
         }
         LOGGER.info("Done loading code modifiers.");
@@ -628,6 +632,6 @@ public class ExtensionManager {
      * Shutdowns all the extensions by unloading them.
      */
     public void shutdown() {
-        this.extensionList.forEach(extension -> unload(extension));
+        this.extensionList.forEach(this::unload);
     }
 }

src/main/java/net/minestom/server/extras/selfmodification/mixins/MinestomBytecodeProvider.java

@@ -18,7 +18,7 @@ public class MinestomBytecodeProvider implements IClassBytecodeProvider {
     }
 
     @Override
-    public ClassNode getClassNode(String name) throws ClassNotFoundException, IOException {
+    public ClassNode getClassNode(String name) throws ClassNotFoundException {
         return getClassNode(name, false);
     }
 

src/main/java/net/minestom/server/network/netty/NettyServer.java

@@ -58,7 +58,8 @@ public final class NettyServer {
 
     private boolean initialized = false;
 
-    private PacketProcessor packetProcessor;
+    private final PacketProcessor packetProcessor;
+    private final GlobalChannelTrafficShapingHandler globalTrafficHandler;
 
     private EventLoopGroup boss, worker;
     private ServerBootstrap bootstrap;
@@ -68,8 +69,6 @@ public final class NettyServer {
     private String address;
     private int port;
 
-    private GlobalChannelTrafficShapingHandler globalTrafficHandler;
-
     /**
      * Scheduler used by {@code globalTrafficHandler}.
      */

src/main/java/net/minestom/server/network/packet/server/play/ChunkDataPacket.java

@@ -137,6 +137,7 @@ public class ChunkDataPacket implements ServerPacket, CacheablePacket {
         return ServerPacketIdentifier.CHUNK_DATA;
     }
 
+    @NotNull
     @Override
     public TemporaryPacketCache getCache() {
         return CACHE;

src/main/java/net/minestom/server/network/packet/server/play/UpdateLightPacket.java

@@ -69,6 +69,7 @@ public class UpdateLightPacket implements ServerPacket, CacheablePacket {
         return ServerPacketIdentifier.UPDATE_LIGHT;
     }
 
+    @NotNull
     @Override
     public TemporaryPacketCache getCache() {
         return CACHE;

src/main/java/net/minestom/server/utils/NamespaceIDHashMap.java

@@ -1,12 +1,18 @@
 package net.minestom.server.utils;
 
-import java.util.*;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.AbstractMap;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
 import java.util.function.Function;
 
 public class NamespaceIDHashMap<V> extends AbstractMap<NamespaceID, V> {
 
     private final Map<NamespaceID, V> backing = new HashMap<>();
 
+    @NotNull
     @Override
     public Set<Entry<NamespaceID, V>> entrySet() {
         return backing.entrySet();

src/main/java/net/minestom/server/utils/Utils.java

@@ -111,9 +111,8 @@ public final class Utils {
             }
         }
 
-        final long[] data = blocksId;
-        writeVarIntBuf(buffer, data.length);
-        for (long datum : data) {
+        writeVarIntBuf(buffer, blocksId.length);
+        for (long datum : blocksId) {
             buffer.writeLong(datum);
         }
     }