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1   /*
2    * Copyright 2012 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package org.jboss.netty.example.http.websocketx.autobahn;
17  
18  import org.jboss.netty.buffer.ChannelBuffers;
19  import org.jboss.netty.channel.ChannelFuture;
20  import org.jboss.netty.channel.ChannelFutureListener;
21  import org.jboss.netty.channel.ChannelHandlerContext;
22  import org.jboss.netty.channel.ExceptionEvent;
23  import org.jboss.netty.channel.MessageEvent;
24  import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
25  import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
26  import org.jboss.netty.handler.codec.http.HttpHeaders;
27  import org.jboss.netty.handler.codec.http.HttpRequest;
28  import org.jboss.netty.handler.codec.http.HttpResponse;
29  import org.jboss.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
30  import org.jboss.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
31  import org.jboss.netty.handler.codec.http.websocketx.ContinuationWebSocketFrame;
32  import org.jboss.netty.handler.codec.http.websocketx.PingWebSocketFrame;
33  import org.jboss.netty.handler.codec.http.websocketx.PongWebSocketFrame;
34  import org.jboss.netty.handler.codec.http.websocketx.TextWebSocketFrame;
35  import org.jboss.netty.handler.codec.http.websocketx.WebSocketFrame;
36  import org.jboss.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
37  import org.jboss.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
38  import org.jboss.netty.logging.InternalLogger;
39  import org.jboss.netty.logging.InternalLoggerFactory;
40  import org.jboss.netty.util.CharsetUtil;
41  
42  import static org.jboss.netty.handler.codec.http.HttpHeaders.*;
43  import static org.jboss.netty.handler.codec.http.HttpMethod.*;
44  import static org.jboss.netty.handler.codec.http.HttpResponseStatus.*;
45  import static org.jboss.netty.handler.codec.http.HttpVersion.*;
46  
47  /**
48   * Handles handshakes and messages
49   */
50  public class AutobahnServerHandler extends SimpleChannelUpstreamHandler {
51      private static final InternalLogger logger = InternalLoggerFactory.getInstance(AutobahnServerHandler.class);
52  
53      private WebSocketServerHandshaker handshaker;
54  
55      @Override
56      public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
57          Object msg = e.getMessage();
58          if (msg instanceof HttpRequest) {
59              handleHttpRequest(ctx, (HttpRequest) msg);
60          } else if (msg instanceof WebSocketFrame) {
61              handleWebSocketFrame(ctx, (WebSocketFrame) msg);
62          }
63      }
64  
65      private void handleHttpRequest(ChannelHandlerContext ctx, HttpRequest req) {
66          // Allow only GET methods.
67          if (req.getMethod() != GET) {
68              sendHttpResponse(ctx, req, new DefaultHttpResponse(HTTP_1_1, FORBIDDEN));
69              return;
70          }
71  
72          // Handshake
73          WebSocketServerHandshakerFactory wsFactory =
74                  new WebSocketServerHandshakerFactory(getWebSocketLocation(req), null, false);
75          handshaker = wsFactory.newHandshaker(req);
76          if (handshaker == null) {
77              wsFactory.sendUnsupportedWebSocketVersionResponse(ctx.getChannel());
78          } else {
79              handshaker.handshake(ctx.getChannel(), req).addListener(WebSocketServerHandshaker.HANDSHAKE_LISTENER);
80          }
81      }
82  
83      private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
84          if (logger.isDebugEnabled()) {
85              logger.debug(String.format(
86                      "Channel %s received %s", ctx.getChannel().getId(), frame.getClass().getSimpleName()));
87          }
88  
89          if (frame instanceof CloseWebSocketFrame) {
90              handshaker.close(ctx.getChannel(), (CloseWebSocketFrame) frame);
91          } else if (frame instanceof PingWebSocketFrame) {
92              ctx.getChannel().write(
93                      new PongWebSocketFrame(frame.isFinalFragment(), frame.getRsv(), frame.getBinaryData()));
94          } else if (frame instanceof TextWebSocketFrame) {
95              // String text = ((TextWebSocketFrame) frame).getText();
96              ctx.getChannel().write(
97                      new TextWebSocketFrame(frame.isFinalFragment(), frame.getRsv(), frame.getBinaryData()));
98          } else if (frame instanceof BinaryWebSocketFrame) {
99              ctx.getChannel().write(
100                     new BinaryWebSocketFrame(frame.isFinalFragment(), frame.getRsv(), frame.getBinaryData()));
101         } else if (frame instanceof ContinuationWebSocketFrame) {
102             ctx.getChannel().write(
103                     new ContinuationWebSocketFrame(frame.isFinalFragment(), frame.getRsv(), frame.getBinaryData()));
104         } else if (frame instanceof PongWebSocketFrame) {
105             // Ignore
106         } else {
107             throw new UnsupportedOperationException(String.format("%s frame types not supported", frame.getClass()
108                     .getName()));
109         }
110     }
111 
112     private static void sendHttpResponse(ChannelHandlerContext ctx, HttpRequest req, HttpResponse res) {
113         // Generate an error page if response status code is not OK (200).
114         if (res.getStatus().getCode() != 200) {
115             res.setContent(ChannelBuffers.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8));
116             setContentLength(res, res.getContent().readableBytes());
117         }
118 
119         // Send the response and close the connection if necessary.
120         ChannelFuture f = ctx.getChannel().write(res);
121         if (!isKeepAlive(req) || res.getStatus().getCode() != 200) {
122             f.addListener(ChannelFutureListener.CLOSE);
123         }
124     }
125 
126     @Override
127     public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
128         e.getCause().printStackTrace();
129         e.getChannel().close();
130     }
131 
132     private static String getWebSocketLocation(HttpRequest req) {
133         return "ws://" + req.headers().get(HttpHeaders.Names.HOST);
134     }
135 }