Use static constructors for ItemStack

src/main/java/org/bukkit/event/player/PlayerItemConsumeEvent.java

@@ -66,7 +66,7 @@ public class PlayerItemConsumeEvent extends PlayerEvent implements Cancellable {
      */
     public void setItem(@Nullable ItemStack item) {
         if (item == null) {
-            this.item = new ItemStack(ItemType.AIR);
+            this.item = ItemStack.of(ItemType.AIR);
         } else {
             this.item = item;
         }

src/main/java/org/bukkit/event/player/PlayerShearEntityEvent.java

@@ -28,7 +28,7 @@ public class PlayerShearEntityEvent extends PlayerEvent implements Cancellable {
 
     @Deprecated
     public PlayerShearEntityEvent(@NotNull final Player who, @NotNull final Entity what) {
-        this(who, what, new ItemStack(ItemType.SHEARS), EquipmentSlot.HAND);
+        this(who, what, ItemStack.of(ItemType.SHEARS), EquipmentSlot.HAND);
     }
 
     @Override

src/main/java/org/bukkit/inventory/ItemStack.java

@@ -24,6 +24,30 @@ import org.jetbrains.annotations.Nullable;
  * returns false.</b>
  */
 public class ItemStack implements Cloneable, ConfigurationSerializable, Translatable {
+
+    /**
+     * Creates a new ItemStack with an amount of 1.
+     *
+     * @param itemType item type
+     * @return A new ItemStack with an amount of 1
+     */
+    @NotNull
+    public static ItemStack of(@NotNull ItemType itemType) {
+        return new ItemStack(itemType);
+    }
+
+    /**
+     * Creates a new ItemStack with the given amount.
+     *
+     * @param itemType item type
+     * @param amount stack size
+     * @return A new ItemStack with the given amount
+     */
+    @NotNull
+    public static ItemStack of(@NotNull ItemType itemType, int amount) {
+        return new ItemStack(itemType, amount);
+    }
+
     private ItemType type = ItemType.AIR;
     private int amount = 0;
     private MaterialData data = null;
@@ -51,7 +75,7 @@ public class ItemStack implements Cloneable, ConfigurationSerializable, Translat
      *
      * @param type item type
      */
-    public ItemStack(@NotNull final ItemType type) {
+    private ItemStack(@NotNull final ItemType type) {
         this(type, 1);
     }
 
@@ -76,7 +100,7 @@ public class ItemStack implements Cloneable, ConfigurationSerializable, Translat
      * @param type item type
      * @param amount stack size
      */
-    public ItemStack(@NotNull final ItemType type, final int amount) {
+    private ItemStack(@NotNull final ItemType type, final int amount) {
         Preconditions.checkArgument(type != null, "Material cannot be null");
         this.type = type;
         this.amount = amount;

src/main/java/org/bukkit/inventory/RecipeChoice.java

@@ -85,7 +85,7 @@ public interface RecipeChoice extends Predicate<ItemStack>, Cloneable {
         @NotNull
         @Override
         public ItemStack getItemStack() {
-            ItemStack stack = new ItemStack(choices.get(0));
+            ItemStack stack = ItemStack.of(choices.get(0));
 
             // For compat
             if (choices.size() > 1) {

src/main/java/org/bukkit/inventory/SmithingTrimRecipe.java

@@ -26,7 +26,7 @@ public class SmithingTrimRecipe extends SmithingRecipe implements ComplexRecipe
      * @param addition The addition ingredient
      */
     public SmithingTrimRecipe(@NotNull NamespacedKey key, @NotNull RecipeChoice template, @NotNull RecipeChoice base, @NotNull RecipeChoice addition) {
-        super(key, new ItemStack(ItemType.AIR), base, addition);
+        super(key, ItemStack.of(ItemType.AIR), base, addition);
         this.template = template;
     }
 

src/main/java/org/bukkit/potion/Potion.java

@@ -265,7 +265,7 @@ public class Potion {
         } else {
             itemType = ItemType.POTION;
         }
-        ItemStack itemStack = new ItemStack(itemType, amount);
+        ItemStack itemStack = ItemStack.of(itemType, amount);
         PotionMeta meta = (PotionMeta) itemStack.getItemMeta();
         meta.setBasePotionData(new PotionData(type, level == 2, extended));
         itemStack.setItemMeta(meta);

src/test/java/org/bukkit/configuration/ConfigurationSectionTest.java

@@ -551,7 +551,7 @@ public abstract class ConfigurationSectionTest extends AbstractTestingBase {
     public void testGetItemStack_String() {
         ConfigurationSection section = getConfigurationSection();
         String key = "exists";
-        ItemStack value = new ItemStack(ItemType.ACACIA_WOOD, 50);
+        ItemStack value = ItemStack.of(ItemType.ACACIA_WOOD, 50);
 
         section.set(key, value);
 
@@ -563,8 +563,8 @@ public abstract class ConfigurationSectionTest extends AbstractTestingBase {
     public void testGetItemStack_String_ItemStack() {
         ConfigurationSection section = getConfigurationSection();
         String key = "exists";
-        ItemStack value = new ItemStack(ItemType.ACACIA_WOOD, 50);
-        ItemStack def = new ItemStack(ItemType.STONE, 1);
+        ItemStack value = ItemStack.of(ItemType.ACACIA_WOOD, 50);
+        ItemStack def = ItemStack.of(ItemType.STONE, 1);
 
         section.set(key, value);
 
@@ -576,7 +576,7 @@ public abstract class ConfigurationSectionTest extends AbstractTestingBase {
     public void testIsItemStack() {
         ConfigurationSection section = getConfigurationSection();
         String key = "exists";
-        ItemStack value = new ItemStack(ItemType.ACACIA_WOOD, 50);
+        ItemStack value = ItemStack.of(ItemType.ACACIA_WOOD, 50);
 
         section.set(key, value);