About java VO

import java.util.Comparator;

public class UserVO{
   private String userId;
   private String userName;

   public static Comparator<UserVO> Compare_By_UserId = new   
         Comparator<UserVO>(){
            @Override
               public int compare( UserVO userA, UserVO userB ){
                  return ( (UserVO) userA ).userId
                     .compareTo( ( (UserVO) userA ).userId );
	      }
	};

   // Business logic method block
   public boolean checkUser(){
      // Do some checks
      return false;
   }
}