Issue 893 (#1014)

* Using static object to reduce memory foot prints

* Updating README along with name of static fields

* Updating code as per review comments

* Updating code as per review comments

* Updating doc as per new code

factory-method/README.md

@@ -42,13 +42,13 @@ public interface Blacksmith {
 
 public class ElfBlacksmith implements Blacksmith {
   public Weapon manufactureWeapon(WeaponType weaponType) {
-    return new ElfWeapon(weaponType);
+    return ELFARSENAL.get(weaponType);
   }
 }
 
 public class OrcBlacksmith implements Blacksmith {
   public Weapon manufactureWeapon(WeaponType weaponType) {
-    return new OrcWeapon(weaponType);
+    return ORCARSENAL.get(weaponType);
   }
 }
 ```