public final class LazySingleton {

  private static volatile LazySingleton instance = null;

  // private constructor

  private LazySingleton() {

  }

  public static LazySingleton getInstance() {

    if (instance == null) {

      synchronized (LazySingleton.class) {

        instance = new LazySingleton();

      }

    }

    return instance;

  }

}