Why are Singleton Classes used in Android/Java, when the same functionality looks to be provided by using a class with static fields and methods?
e.g.
public class StaticClass { private static int foo = 0; public static void setFoo(int f) { foo = f; } public static int getFoo() { return foo; } } vs
public class SingletonClass implements Serializable { private static volatile SingletonClass sSoleInstance; private int foo; //private constructor. private SingletonClass(){ //Prevent form the reflection api. if (sSoleInstance != null){ throw new RuntimeException("Use getInstance() method to get the single instance of this class."); } foo = 0; } public static SingletonClass getInstance() { if (sSoleInstance == null) { //if there is no instance available... create new one synchronized (SingletonClass.class) { if (sSoleInstance == null) sSoleInstance = new SingletonClass(); } } return sSoleInstance; } //Make singleton from serialize and deserialize operation. protected SingletonClass readResolve() { return getInstance(); } public void setFoo(int foo) { this.foo = foo; } public int getFoo() { return foo; } } 
