Added ItemStack#getAirItem

src/main/java/fr/themode/minestom/entity/Entity.java

@@ -247,7 +247,7 @@ public abstract class Entity implements Viewable, DataContainer {
 
                     int firstBlock = 0;
                     for (int y = (int) position.getY(); y > 0; y--) {
-                        BlockPosition blockPosition = new BlockPosition(position.getX(), y + 1, position.getZ());
+                        BlockPosition blockPosition = new BlockPosition(position.getX(), y, position.getZ());
                         short blockId = instance.getBlockId(blockPosition);
                         //if (y == 70)
                         //   System.out.println("id: " + blockId);

src/main/java/fr/themode/minestom/entity/EntityCreature.java

@@ -139,7 +139,7 @@ public abstract class EntityCreature extends LivingEntity {
         pathFinder.getPath(position, blockPositions -> {
             if (blockPositions.isEmpty()) {
                 // Didn't find path
-                System.out.println("NOT FOUND");
+                System.out.println("PATH NOT FOUND");
                 return;
             }
             this.blockPositions = blockPositions;

src/main/java/fr/themode/minestom/entity/Player.java

@@ -82,10 +82,10 @@ public class Player extends LivingEntity {
     private float fieldViewModifier = 0.1f;
 
     // Statistics
-    private Map<PlayerStatistic, Integer> statisticValueMap = new HashMap<>();
+    private Map<PlayerStatistic, Integer> statisticValueMap = new Hashtable<>();
 
     // Vehicle
-    private PlayerVehicleInformation vehicleInformation;
+    private PlayerVehicleInformation vehicleInformation = new PlayerVehicleInformation();
 
     public Player(UUID uuid, String username, PlayerConnection playerConnection) {
         super(EntityType.PLAYER.getId());

src/main/java/fr/themode/minestom/inventory/Inventory.java

@@ -42,7 +42,10 @@ public class Inventory implements InventoryModifier, InventoryClickHandler, View
         this.offset = inventoryType.getAdditionalSlot();
 
         this.itemStacks = new ItemStack[inventoryType.getAdditionalSlot()];
-        Arrays.fill(itemStacks, ItemStack.AIR_ITEM);
+
+        for (int i = 0; i < itemStacks.length; i++) {
+            itemStacks[i] = ItemStack.getAirItem();
+        }
     }
 
     private static int generateId() {
@@ -117,12 +120,12 @@ public class Inventory implements InventoryModifier, InventoryClickHandler, View
     }
 
     public ItemStack getCursorItem(Player player) {
-        return cursorPlayersItem.getOrDefault(player, ItemStack.AIR_ITEM);
+        return cursorPlayersItem.getOrDefault(player, ItemStack.getAirItem());
     }
 
     private void safeItemInsert(int slot, ItemStack itemStack) {
         synchronized (this) {
-            itemStack = itemStack == null ? ItemStack.AIR_ITEM : itemStack;
+            itemStack = itemStack == null ? ItemStack.getAirItem() : itemStack;
             this.itemStacks[slot] = itemStack;
             SetSlotPacket setSlotPacket = new SetSlotPacket();
             setSlotPacket.windowId = 1;

src/main/java/fr/themode/minestom/inventory/PlayerInventory.java

@@ -23,7 +23,7 @@ public class PlayerInventory implements InventoryModifier, InventoryClickHandler
 
     private Player player;
     private ItemStack[] items = new ItemStack[INVENTORY_SIZE];
-    private ItemStack cursorItem = ItemStack.AIR_ITEM;
+    private ItemStack cursorItem = ItemStack.getAirItem();
 
     private InventoryCondition inventoryCondition;
     private InventoryClickProcessor clickProcessor = new InventoryClickProcessor();
@@ -31,7 +31,9 @@ public class PlayerInventory implements InventoryModifier, InventoryClickHandler
     public PlayerInventory(Player player) {
         this.player = player;
 
-        Arrays.fill(items, ItemStack.AIR_ITEM);
+        for (int i = 0; i < items.length; i++) {
+            items[i] = ItemStack.getAirItem();
+        }
     }
 
     @Override
@@ -176,13 +178,14 @@ public class PlayerInventory implements InventoryModifier, InventoryClickHandler
                 return getLeggings();
             case BOOTS:
                 return getBoots();
+            default:
+                throw new NullPointerException("Equipment slot cannot be null");
         }
-        return ItemStack.AIR_ITEM;
     }
 
     private void safeItemInsert(int slot, ItemStack itemStack) {
         synchronized (this) {
-            itemStack = itemStack == null ? ItemStack.AIR_ITEM : itemStack;
+            itemStack = itemStack == null ? ItemStack.getAirItem() : itemStack;
 
             EntityEquipmentPacket.Slot equipmentSlot;
 

src/main/java/fr/themode/minestom/inventory/click/InventoryClickProcessor.java

@@ -136,12 +136,12 @@ public class InventoryClickProcessor {
 
         if (clicked.isAir()) {
             // Set held item [key] to slot
-            resultClicked = ItemStack.AIR_ITEM;
+            resultClicked = ItemStack.getAirItem();
             resultHeld = clicked.clone();
         } else {
             if (cursor.isAir()) {
                 // if held item [key] is air then set clicked to held
-                resultClicked = ItemStack.AIR_ITEM;
+                resultClicked = ItemStack.getAirItem();
                 resultHeld = clicked.clone();
             } else {
                 // Otherwise replace held item and held
@@ -218,7 +218,7 @@ public class InventoryClickProcessor {
 
                     // Switch
                     itemSetter.accept(index, resultClicked);
-                    itemSetter.accept(slot, ItemStack.AIR_ITEM);
+                    itemSetter.accept(slot, ItemStack.getAirItem());
                     filled = true;
                     break;
                 }
@@ -347,7 +347,7 @@ public class InventoryClickProcessor {
 
     public InventoryClickResult doubleClick(InventoryCondition inventoryCondition, Player player, int slot,
                                             ItemStack cursor, InventoryClickLoopHandler... loopHandlers) {
-        InventoryClickResult clickResult = new InventoryClickResult(ItemStack.AIR_ITEM, cursor);
+        InventoryClickResult clickResult = new InventoryClickResult(ItemStack.getAirItem(), cursor);
 
         if (clickResult.isCancel()) {
             return clickResult;

src/main/java/fr/themode/minestom/item/ItemStack.java

@@ -8,7 +8,10 @@ import java.util.ArrayList;
 
 public class ItemStack implements DataContainer {
 
-    public static final ItemStack AIR_ITEM = new ItemStack((short) 0, (byte) 0);
+    public static ItemStack getAirItem() {
+        return new ItemStack((short) 0, (byte) 0);
+    }
+
     private static StackingRule defaultStackingRule;
 
     private short materialId;

src/main/java/fr/themode/minestom/item/rule/VanillaStackingRule.java

@@ -22,7 +22,7 @@ public class VanillaStackingRule extends StackingRule {
     @Override
     public ItemStack apply(ItemStack item, int newAmount) {
         if (newAmount <= 0)
-            return ItemStack.AIR_ITEM;
+            return ItemStack.getAirItem();
 
         item.setAmount((byte) newAmount);
         return item;

src/main/java/fr/themode/minestom/listener/PlayerDiggingListener.java

@@ -66,7 +66,7 @@ public class PlayerDiggingListener {
                 break;
             case DROP_ITEM_STACK:
                 ItemStack droppedItemStack = player.getInventory().getItemInMainHand().clone();
-                dropItem(player, droppedItemStack, ItemStack.AIR_ITEM);
+                dropItem(player, droppedItemStack, ItemStack.getAirItem());
                 break;
             case DROP_ITEM:
                 ItemStack droppedItemStack2 = player.getInventory().getItemInMainHand().clone();
@@ -74,7 +74,7 @@ public class PlayerDiggingListener {
 
                 ItemStack handItem = player.getInventory().getItemInMainHand();
                 handItem.setAmount((byte) (handItem.getAmount() - 1));
-                handItem = handItem.getAmount() <= 0 ? ItemStack.AIR_ITEM : handItem;
+                handItem = handItem.getAmount() <= 0 ? ItemStack.getAirItem() : handItem;
 
                 dropItem(player, droppedItemStack2, handItem);
                 break;

src/main/java/fr/themode/minestom/listener/UseItemListener.java

@@ -42,9 +42,9 @@ public class UseItemListener {
             ItemStack armorItem = armorEquipEvent.getArmorItem();
 
             if (hand == Player.Hand.MAIN) {
-                playerInventory.setItemInMainHand(ItemStack.AIR_ITEM);
+                playerInventory.setItemInMainHand(ItemStack.getAirItem());
             } else {
-                playerInventory.setItemInOffHand(ItemStack.AIR_ITEM);
+                playerInventory.setItemInOffHand(ItemStack.getAirItem());
             }
 
             switch (armorSlot) {

src/main/java/fr/themode/minestom/recipe/ShapedRecipe.java

@@ -12,7 +12,7 @@ public class ShapedRecipe extends Recipe {
 
     private List<DeclareRecipesPacket.Ingredient> ingredients = new ArrayList<>();
 
-    private ItemStack result = ItemStack.AIR_ITEM;
+    private ItemStack result = ItemStack.getAirItem();
 
     public ShapedRecipe(String recipeId, String group, int width, int height) {
         super(RecipeType.SHAPED, recipeId);

src/main/java/fr/themode/minestom/recipe/ShapelessRecipe.java

@@ -10,7 +10,7 @@ public class ShapelessRecipe extends Recipe {
 
     private List<DeclareRecipesPacket.Ingredient> ingredients = new ArrayList<>();
 
-    private ItemStack result = ItemStack.AIR_ITEM;
+    private ItemStack result = ItemStack.getAirItem();
 
     public ShapelessRecipe(String recipeId, String group) {
         super(RecipeType.SHAPELESS, recipeId);

src/main/java/fr/themode/minestom/recipe/SmeltingRecipe.java

@@ -7,7 +7,7 @@ public class SmeltingRecipe extends Recipe {
 
     private DeclareRecipesPacket.Ingredient ingredient;
 
-    private ItemStack result = ItemStack.AIR_ITEM;
+    private ItemStack result = ItemStack.getAirItem();
 
     private float experience;
 

src/main/java/fr/themode/minestom/utils/Utils.java

@@ -141,13 +141,13 @@ public class Utils {
         boolean present = reader.readBoolean();
 
         if (!present) {
-            return ItemStack.AIR_ITEM;
+            return ItemStack.getAirItem();
         }
 
         int id = reader.readVarInt();
         if (id == -1) {
             // Drop mode
-            return ItemStack.AIR_ITEM;
+            return ItemStack.getAirItem();
         }
 
         byte count = reader.readByte();