Added enum singleton for reference sake

Author: pjhamilton4

src/main/java/com/philipjhamilton/App.java

@@ -1,6 +1,6 @@
 package com.philipjhamilton;
 
-import com.philipjhamilton.patterns.creational.singleton.Singleton;
+import com.philipjhamilton.patterns.creational.singleton.SingletonLazyInit;
 
 /**
  * Hello world!
@@ -10,7 +10,7 @@ public class App
 {
     public static void main( String[] args )
     {
-        Singleton test = Singleton.getInstance();
+        SingletonLazyInit test = SingletonLazyInit.getInstance();
 
     }
 }

src/main/java/com/philipjhamilton/patterns/creational/singleton/SingletonEnum.java

@@ -0,0 +1,17 @@
+package com.philipjhamilton.patterns.creational.singleton;
+
+public enum SingletonEnum {
+
+    INSTANCE;
+
+    int value;
+
+    public int getValue(){
+        return value;
+    }
+
+    public void setValue(int value){
+        this.value = value;
+    }
+
+}

src/main/java/com/philipjhamilton/patterns/creational/singleton/Singleton.java renamed to src/main/java/com/philipjhamilton/patterns/creational/singleton/SingletonLazyInit.java

@@ -3,21 +3,21 @@
 import java.io.Serializable;
 import java.util.HashMap;
 
-public class Singleton implements Serializable {
+public class SingletonLazyInit implements Serializable {
 
-    private static volatile Singleton instance = null;
+    private static volatile SingletonLazyInit instance = null;
     private static HashMap<String, String> data = new HashMap<String, String>();
 
-    private Singleton(){
+    private SingletonLazyInit(){
         if (instance != null){
             throw new RuntimeException("Use getInstance() method to get the single instance of this class.");
         }
     }
 
-    public static Singleton getInstance(){
+    public static SingletonLazyInit getInstance(){
         if (instance == null){ //if there is no instance available... create new one
-            synchronized(Singleton.class){
-                if (instance == null) instance = new Singleton();
+            synchronized(SingletonLazyInit.class){
+                if (instance == null) instance = new SingletonLazyInit();
             }
         }
 
@@ -26,7 +26,7 @@ public static Singleton getInstance(){
 
     // TODO - Implement some functionality to pull data or do tasks
 
-    protected Singleton readResolve() {
+    protected SingletonLazyInit readResolve() {
         return getInstance();
     }
 }