package biz.xsoftware.examples.listener2;

 import java.util.HashSet;

 /**

  */

 public class UserReplicationServiceImpl implements UserReplicationService

 {

     private UserService userSvc;

     private HashSet<String> users = new HashSet<String>();

     /**

      * Creates an instance of UserReplicationServiceImpl.

      * @param service

      */

     public UserReplicationServiceImpl(UserService service)

     {

         this.userSvc = service;

         userSvc.addUserListener(new MyUserListener());

     }

     /**

      * @see biz.xsoftware.examples.listener2.UserReplicationService#doesUserExist(java.lang.String)

      */

     public boolean doesUserExist(String user)

     {

         return users.contains(user);

     }

     private class MyUserListener implements UserListener {

         /**

          * @see biz.xsoftware.examples.listener2.UserListener#userAdded(java.lang.String)

          */

         public void userAdded(String userName)

         {

             users.add(userName);

         }

         /**

          * @see biz.xsoftware.examples.listener2.UserListener#userDeleted(java.lang.String)

          */

         public void userDeleted(String userName)

         {

             users.remove(userName);

         }

     }

 }