singletone java code example

Example 1: java singleton

public final class SomeSingleton {
   public static final SomeSingleton INSTANCE;

   private SomeSingleton() {
      INSTANCE = (SomeSingleton)this;
      System.out.println("init complete");
   }

   static {
      new SomeSingleton();
   }
}

Example 2: java singleton

public class SingletonOnDemand {
	
	private SingletonOnDemand () {}
	private static class Singleton {
		private static final SingletonOnDemand instance = new SingletonOnDemand();
	}
	
	public static SingletonOnDemand getInstance () {
		System.out.println("create instance");
		return Singleton.instance;
	}
}