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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.UpgradeRequest;
52  import org.eclipse.jetty.websocket.api.UpgradeResponse;
53  import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
54  import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
55  import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
56  import org.eclipse.jetty.websocket.api.annotations.WebSocket;
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(UpgradeRequest req, UpgradeResponse 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                 try
110                 {
111                     session.close();
112                 }
113                 catch (IOException ignore)
114                 {
115                     // ignore
116                 }
117                 return;
118             }
119 
120             ListIterator<ChatWebSocket> iter = members.listIterator();
121             while (iter.hasNext())
122             {
123                 ChatWebSocket member = iter.next();
124 
125                 // Test if member is now disconnected
126                 if (!member.session.isOpen())
127                 {
128                     iter.remove();
129                     continue;
130                 }
131 
132                 // Async write the message back.
133                 member.remote.sendStringByFuture(data);
134             }
135         }
136 
137         @OnWebSocketClose
138         public void onClose(int code, String message)
139         {
140             members.remove(this);
141         }
142     }
143 }