IODH

Zero Syncronization issues ! Simple ! Clean !

public class Something {
private Something() {
}

private static class LazyHolder {
private static final Something INSTANCE = new Something();
}

public static final Something getInstance() {
return LazyHolder.INSTANCE;
}
}

OR

static Singleton instance;

public static synchronized Singleton getInstance() {
if (instance == null)
instance == new Singleton();
return instance;
}

Why it is called LAZY ? : IODH utilizes lazy class initialization. The JVM won't execute a class's static initializer until you actually touch something in the class. This applies to static nested classes, too...

Read more on : wikipedia , Double-checked_locking