Singleton

Question 1

Ways of creating Singleton Object

Answer 1

1. Method level synchronization:
   public synchronized Singleton getInstance(){
    } 
2. Double locking with Volatile :
     public Singleton getInstance(){
      if(instance == null){
       synchronized(singleton.class){
            if(instance == null)
                   singleton = new Singleton()

    }

3. Early Initialization :
  private static Singleton INSTANCE = new Singleton();

4. Lazy Initialization with StaticInstanceHolder class:

static class InstanctHolder{
private Singleton INSTANCE = new Singleton();
}
public Singleton getInstance(){
return InstanceHolder.INSTANCE;
}