Being absolutely sure

eco-core/core-nms/v1_16_R3/src/main/java/com/willfp/eco/proxy/v1_16_R3/FastItemStackUtils.java

@@ -0,0 +1,43 @@
+package com.willfp.eco.proxy.v1_16_R3;
+
+import org.bukkit.craftbukkit.libs.org.apache.commons.lang3.Validate;
+import org.bukkit.craftbukkit.v1_16_R3.inventory.CraftItemStack;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.Field;
+
+public class FastItemStackUtils {
+    private static final Field FIELD;
+
+    public static net.minecraft.server.v1_16_R3.ItemStack getNMSStack(@NotNull final ItemStack itemStack) {
+        if (!(itemStack instanceof CraftItemStack)) {
+            return CraftItemStack.asNMSCopy(itemStack);
+        } else {
+            try {
+                net.minecraft.server.v1_16_R3.ItemStack nms = (net.minecraft.server.v1_16_R3.ItemStack) FIELD.get(itemStack);
+                return nms == null ? CraftItemStack.asNMSCopy(itemStack) : nms;
+            } catch (ReflectiveOperationException e) {
+                e.printStackTrace();
+                return net.minecraft.server.v1_16_R3.ItemStack.b;
+            }
+        }
+    }
+
+    static {
+        Field temp = null;
+
+        try {
+            Field handleField = CraftItemStack.class.getDeclaredField("handle");
+            handleField.setAccessible(true);
+            temp = handleField;
+        } catch (ReflectiveOperationException e) {
+            e.printStackTrace();
+        }
+
+        assert temp != null;
+        Validate.notNull(temp, "Error occurred in initialization!");
+
+        FIELD = temp;
+    }
+}

eco-core/core-nms/v1_16_R3/src/main/kotlin/com/willfp/eco/proxy/v1_16_R3/fast/NMSFastItemStack.kt

@@ -1,6 +1,7 @@
 package com.willfp.eco.proxy.v1_16_R3.fast
 
 import com.willfp.eco.internal.fast.EcoFastItemStack
+import com.willfp.eco.proxy.v1_16_R3.FastItemStackUtils
 import com.willfp.eco.util.StringUtils
 import net.minecraft.server.v1_16_R3.*
 import org.bukkit.craftbukkit.v1_16_R3.inventory.CraftItemStack
@@ -11,7 +12,7 @@ import java.lang.reflect.Field
 import kotlin.experimental.and
 
 class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemStack<ItemStack>(
-    getNMSStack(itemStack)!!, itemStack
+    FastItemStackUtils.getNMSStack(itemStack), itemStack
 ) {
     private var loreCache: List<String>? = null
     override fun getEnchantmentsOnItem(checkStored: Boolean): Map<Enchantment, Int> {

eco-core/core-nms/v1_17_R1/src/main/java/com/willfp/eco/proxy/v1_17_R1/FastItemStackUtils.java

@@ -0,0 +1,45 @@
+package com.willfp.eco.proxy.v1_17_R1;
+
+import lombok.experimental.UtilityClass;
+import org.bukkit.craftbukkit.libs.org.apache.commons.lang3.Validate;
+import org.bukkit.craftbukkit.v1_17_R1.inventory.CraftItemStack;
+import org.bukkit.inventory.ItemStack;
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.Field;
+
+@UtilityClass
+public class FastItemStackUtils {
+    private static final Field FIELD;
+
+    public static net.minecraft.world.item.ItemStack getNMSStack(@NotNull final ItemStack itemStack) {
+        if (!(itemStack instanceof CraftItemStack)) {
+            return CraftItemStack.asNMSCopy(itemStack);
+        } else {
+            try {
+                net.minecraft.world.item.ItemStack nms = (net.minecraft.world.item.ItemStack) FIELD.get(itemStack);
+                return nms == null ? CraftItemStack.asNMSCopy(itemStack) : nms;
+            } catch (ReflectiveOperationException e) {
+                e.printStackTrace();
+                return net.minecraft.world.item.ItemStack.EMPTY;
+            }
+        }
+    }
+
+    static {
+        Field temp = null;
+
+        try {
+            Field handleField = CraftItemStack.class.getDeclaredField("handle");
+            handleField.setAccessible(true);
+            temp = handleField;
+        } catch (ReflectiveOperationException e) {
+            e.printStackTrace();
+        }
+
+        assert temp != null;
+        Validate.notNull(temp, "Error occurred in initialization!");
+
+        FIELD = temp;
+    }
+}

eco-core/core-nms/v1_17_R1/src/main/kotlin/com/willfp/eco/proxy/v1_17_R1/fast/NMSFastItemStack.kt

@@ -1,6 +1,7 @@
 package com.willfp.eco.proxy.v1_17_R1.fast
 
 import com.willfp.eco.internal.fast.EcoFastItemStack
+import com.willfp.eco.proxy.v1_17_R1.FastItemStackUtils
 import com.willfp.eco.util.StringUtils
 import net.minecraft.nbt.CompoundTag
 import net.minecraft.nbt.ListTag
@@ -12,11 +13,10 @@ import org.bukkit.craftbukkit.v1_17_R1.inventory.CraftItemStack
 import org.bukkit.craftbukkit.v1_17_R1.util.CraftMagicNumbers
 import org.bukkit.craftbukkit.v1_17_R1.util.CraftNamespacedKey
 import org.bukkit.enchantments.Enchantment
-import java.lang.reflect.Field
 import kotlin.experimental.and
 
 class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemStack<ItemStack>(
-    getNMSStack(itemStack)!!, itemStack
+    FastItemStackUtils.getNMSStack(itemStack), itemStack
 ) {
     private var loreCache: List<String>? = null
 
@@ -120,28 +120,4 @@ class NMSFastItemStack(itemStack: org.bukkit.inventory.ItemStack) : EcoFastItemS
             bukkit.itemMeta = CraftItemStack.asCraftMirror(handle).itemMeta
         }
     }
-
-    companion object {
-        private var field: Field
-
-        init {
-            lateinit var temp: Field
-            try {
-                val handleField = CraftItemStack::class.java.getDeclaredField("handle")
-                handleField.isAccessible = true
-                temp = handleField
-            } catch (e: ReflectiveOperationException) {
-                e.printStackTrace()
-            }
-            field = temp
-        }
-
-        fun getNMSStack(itemStack: org.bukkit.inventory.ItemStack): ItemStack? {
-            return if (itemStack !is CraftItemStack) {
-                CraftItemStack.asNMSCopy(itemStack)
-            } else {
-                field.get(itemStack) as ItemStack
-            }
-        }
-    }
 }