public class Singleton {
// Private constructor prevents instantiation from other classes
private Singleton() { }

/**
* SingletonHolder is loaded on the first execution of Singleton.getInstance()
* or the first access to SingletonHolder.INSTANCE, not before.
*/
private static class SingletonHolder {
public static final Singleton INSTANCE = new Singleton();
}

public static Singleton getInstance() {
return SingletonHolder.INSTANCE;
}
}