Make fields final if possible to ensure immutability

src/main/java/appeng/util/item/AEItemDef.java

@@ -17,8 +17,8 @@ public class AEItemDef
 
 	public int def;
 
-	private int itemID;
-	public Item item;
+	private final int itemID;
+	public final Item item;
 	public int damageValue;
 
 	public int displayDamage;
@@ -37,8 +37,8 @@ public class AEItemDef
 
 	public OreReference isOre;
 
-	static AESharedNBT lowTag = new AESharedNBT( Integer.MIN_VALUE );
-	static AESharedNBT highTag = new AESharedNBT( Integer.MAX_VALUE );
+	static final AESharedNBT lowTag = new AESharedNBT( Integer.MIN_VALUE );
+	static final AESharedNBT highTag = new AESharedNBT( Integer.MAX_VALUE );
 
 	public AEItemDef(Item it) {
 		item = it;

src/main/java/appeng/util/item/AESharedNBT.java

@@ -18,8 +18,9 @@ import appeng.util.Platform;
 public class AESharedNBT extends NBTTagCompound implements IAETagCompound
 {
 
-	private Item item;
-	private int meta, hash;
+	private final Item item;
+	private final int meta;
+	private int hash;
 	public SharedSearchObject sso;
 	private IItemComparison comp;
 
@@ -120,7 +121,7 @@ public class AESharedNBT extends NBTTagCompound implements IAETagCompound
 	/*
 	 * Shared Tag Compound Cache.
 	 */
-	private static WeakHashMap<SharedSearchObject, WeakReference<SharedSearchObject>> sharedTagCompounds = new WeakHashMap<SharedSearchObject, WeakReference<SharedSearchObject>>();
+	private static final WeakHashMap<SharedSearchObject, WeakReference<SharedSearchObject>> sharedTagCompounds = new WeakHashMap<SharedSearchObject, WeakReference<SharedSearchObject>>();
 
 	/*
 	 * Debug purposes.

src/main/java/appeng/util/item/OreHelper.java

@@ -11,7 +11,7 @@ import appeng.api.storage.data.IAEItemStack;
 public class OreHelper
 {
 
-	public static OreHelper instance = new OreHelper();
+	public static final OreHelper instance = new OreHelper();
 
 	class ItemRef
 	{
@@ -28,9 +28,9 @@ public class OreHelper
 			hash = ref.hashCode() ^ damage;
 		}
 
-		Item ref;
-		int damage;
-		int hash;
+		final Item ref;
+		final int damage;
+		final int hash;
 
 		@Override
 		public boolean equals(Object obj)
@@ -58,7 +58,7 @@ public class OreHelper
 
 	}
 
-	HashMap<ItemRef, OreResult> references = new HashMap<ItemRef, OreResult>();
+	final HashMap<ItemRef, OreResult> references = new HashMap<ItemRef, OreResult>();
 
 	public OreReference isOre(ItemStack ItemStack)
 	{

src/main/java/appeng/util/item/OreReference.java

@@ -12,9 +12,9 @@ import appeng.api.storage.data.IAEItemStack;
 public class OreReference
 {
 
-	private LinkedList<ItemStack> otherOptions = new LinkedList<ItemStack>();
+	private final LinkedList<ItemStack> otherOptions = new LinkedList<ItemStack>();
 	private ArrayList<IAEItemStack> aeOtherOptions = null;
-	private HashSet<Integer> ores = new HashSet<Integer>();
+	private final HashSet<Integer> ores = new HashSet<Integer>();
 
 	public Collection<ItemStack> getEquivalents()
 	{

src/main/java/appeng/util/item/SharedSearchObject.java

@@ -7,8 +7,8 @@ import appeng.util.Platform;
 public class SharedSearchObject
 {
 
-	int def;
-	int hash;
+	final int def;
+	final int hash;
 	NBTTagCompound compound;
 	public AESharedNBT shared;