singleton pattern in java. lazy initialization

Question

public static MySingleton getInstance() {
 if (_instance==null) {
   synchronized (MySingleton.class) {
      _instance = new MySingleton();
   }
 }
 return _instanc         


        

Answer 1

I would suggest the following implementation

public class MySingleTon
{

  private static MySingleton obj;

  //private Constructor
  private MySingleTon()
  {
  }


  public static MySingleTon getInstance()
  {
     if(obj==null)
     {
        synchronized(MySingleTon.class)
        {
         if(obj == null)
         {
             obj = new MySingleTon();
         }
        }
     }
     return obj;    
  }
}