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1   //
2   //  ========================================================================
3   //  Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
4   //  ------------------------------------------------------------------------
5   //  All rights reserved. This program and the accompanying materials
6   //  are made available under the terms of the Eclipse Public License v1.0
7   //  and Apache License v2.0 which accompanies this distribution.
8   //
9   //      The Eclipse Public License is available at
10  //      http://www.eclipse.org/legal/epl-v10.html
11  //
12  //      The Apache License v2.0 is available at
13  //      http://www.opensource.org/licenses/apache2.0.php
14  //
15  //  You may elect to redistribute this code under either of these licenses.
16  //  ========================================================================
17  //
18  
19  //
20  
21  //  ========================================================================
22  //  Copyright (c) 1995-2012 Mort Bay Consulting Pty. Ltd.
23  //  ------------------------------------------------------------------------
24  //  All rights reserved. This program and the accompanying materials
25  //  are made available under the terms of the Eclipse Public License v1.0
26  //  and Apache License v2.0 which accompanies this distribution.
27  //
28  //      The Eclipse Public License is available at
29  //      http://www.eclipse.org/legal/epl-v10.html
30  //
31  //      The Apache License v2.0 is available at
32  //      http://www.opensource.org/licenses/apache2.0.php
33  //
34  //  You may elect to redistribute this code under either of these licenses.
35  //  ========================================================================
36  //
37  
38  package com.acme;
39  
40  import java.io.IOException;
41  import java.util.List;
42  import java.util.ListIterator;
43  import java.util.concurrent.CopyOnWriteArrayList;
44  
45  import javax.servlet.ServletException;
46  import javax.servlet.http.HttpServletRequest;
47  import javax.servlet.http.HttpServletResponse;
48  
49  import org.eclipse.jetty.websocket.api.RemoteEndpoint;
50  import org.eclipse.jetty.websocket.api.Session;
51  import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
52  import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
53  import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
54  import org.eclipse.jetty.websocket.api.annotations.WebSocket;
55  import org.eclipse.jetty.websocket.servlet.ServletUpgradeRequest;
56  import org.eclipse.jetty.websocket.servlet.ServletUpgradeResponse;
57  import org.eclipse.jetty.websocket.servlet.WebSocketCreator;
58  import org.eclipse.jetty.websocket.servlet.WebSocketServlet;
59  import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
60  
61  @SuppressWarnings("serial")
62  public class WebSocketChatServlet extends WebSocketServlet implements WebSocketCreator
63  {
64      /** Holds active sockets to other members of the chat */
65      private final List<ChatWebSocket> members = new CopyOnWriteArrayList<ChatWebSocket>();
66  
67      @Override
68      protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
69      {
70          getServletContext().getNamedDispatcher("default").forward(request,response);
71      }
72  
73      @Override
74      public Object createWebSocket(ServletUpgradeRequest req, ServletUpgradeResponse resp)
75      {
76          return new ChatWebSocket();
77      }
78  
79      @Override
80      public void configure(WebSocketServletFactory factory)
81      {
82          factory.register(ChatWebSocket.class);
83          factory.setCreator(this);
84      }
85  
86      /* ------------------------------------------------------------ */
87      /**
88       * Create a WebSocket that echo's back the message to all other members of the servlet.
89       */
90      @WebSocket
91      public class ChatWebSocket
92      {
93          volatile Session session;
94          volatile RemoteEndpoint remote;
95  
96          @OnWebSocketConnect
97          public void onOpen(Session sess)
98          {
99              this.session = sess;
100             this.remote = sess.getRemote();
101             members.add(this);
102         }
103 
104         @OnWebSocketMessage
105         public void onMessage(String data)
106         {
107             if (data.contains("disconnect"))
108             {
109                 session.close();
110                 return;
111             }
112 
113             ListIterator<ChatWebSocket> iter = members.listIterator();
114             while (iter.hasNext())
115             {
116                 ChatWebSocket member = iter.next();
117 
118                 // Test if member is now disconnected
119                 if (!member.session.isOpen())
120                 {
121                     iter.remove();
122                     continue;
123                 }
124 
125                 // Async write the message back.
126                 member.remote.sendString(data,null);
127             }
128         }
129 
130         @OnWebSocketClose
131         public void onClose(int code, String message)
132         {
133             members.remove(this);
134         }
135     }
136 }