Java Instance return model note!

1. We have a class and define a static method of  getInstance()

 

public   class  GenDarwinGlobal  extends  GenDarwinGlobalHelper
{
     /**
     * Script Name   : <b>GenDarwinGlobal</b>
     * Generated     : <b>Mar 31, 2011 1:16:48 AM</b>
     * Description   : Functional Test Script
     * Original Host : WinNT Version 5.2  Build 3790 (S)
     * 
     *  @since   2011/03/31
     *  @author  dwei
      */
     public   void  testMain(Object[] args) 
    {
         //  TODO Insert code here
    }
     public    static  GenDarwinGlobal getInstance()
    {
         return   new  GenDarwinGlobal();
    }
}

 

2. Compare these code line, the getInstance sequence will get failed return because it has two new instance belong to different object.

//         FucLib.GenevaFuc.GenDarwinGlobal.getInstance().openBuyTransaction();
     //     FucLib.GenevaFuc.GenDarwinGlobal.getInstance().ClickQuery();
        
        
        FucLib.GenevaFuc.GenDarwinGlobal oGD  =    new  FucLib.GenevaFuc.GenDarwinGlobal(); 
        oGD.openBuyTransaction();
        oGD.ClickQuery();

3. Also we can using this method to resolve this problem in the instance code .

 

private   static  GenDarwinGlobal instance  =   null ;
public   static   synchronized  GenDarwinGlobal getInstance()
{
    if ( instance  ==   null )
   {
    instance  =   new  GenDarwinGlobal();
   }
     return  instance;
}