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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.server;
17  
18  import static org.jboss.netty.handler.codec.http.HttpHeaders.*;
19  import static org.jboss.netty.handler.codec.http.HttpHeaders.Names.*;
20  import static org.jboss.netty.handler.codec.http.HttpMethod.*;
21  import static org.jboss.netty.handler.codec.http.HttpResponseStatus.*;
22  import static org.jboss.netty.handler.codec.http.HttpVersion.*;
23  
24  import org.jboss.netty.buffer.ChannelBuffer;
25  import org.jboss.netty.buffer.ChannelBuffers;
26  import org.jboss.netty.channel.ChannelFuture;
27  import org.jboss.netty.channel.ChannelFutureListener;
28  import org.jboss.netty.channel.ChannelHandlerContext;
29  import org.jboss.netty.channel.ExceptionEvent;
30  import org.jboss.netty.channel.MessageEvent;
31  import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
32  import org.jboss.netty.handler.codec.http.DefaultHttpResponse;
33  import org.jboss.netty.handler.codec.http.HttpRequest;
34  import org.jboss.netty.handler.codec.http.HttpResponse;
35  import org.jboss.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
36  import org.jboss.netty.handler.codec.http.websocketx.PingWebSocketFrame;
37  import org.jboss.netty.handler.codec.http.websocketx.PongWebSocketFrame;
38  import org.jboss.netty.handler.codec.http.websocketx.TextWebSocketFrame;
39  import org.jboss.netty.handler.codec.http.websocketx.WebSocketFrame;
40  import org.jboss.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
41  import org.jboss.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
42  import org.jboss.netty.logging.InternalLogger;
43  import org.jboss.netty.logging.InternalLoggerFactory;
44  import org.jboss.netty.util.CharsetUtil;
45  
46  /**
47   * Handles handshakes and messages
48   */
49  public class WebSocketServerHandler extends SimpleChannelUpstreamHandler {
50      private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocketServerHandler.class);
51  
52      private static final String WEBSOCKET_PATH = "/websocket";
53  
54      private WebSocketServerHandshaker handshaker;
55  
56      @Override
57      public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
58          Object msg = e.getMessage();
59          if (msg instanceof HttpRequest) {
60              handleHttpRequest(ctx, (HttpRequest) msg);
61          } else if (msg instanceof WebSocketFrame) {
62              handleWebSocketFrame(ctx, (WebSocketFrame) msg);
63          }
64      }
65  
66      private void handleHttpRequest(ChannelHandlerContext ctx, HttpRequest req) throws Exception {
67          // Allow only GET methods.
68          if (req.getMethod() != GET) {
69              sendHttpResponse(ctx, req, new DefaultHttpResponse(HTTP_1_1, FORBIDDEN));
70              return;
71          }
72  
73          // Send the demo page and favicon.ico
74          if (req.getUri().equals("/")) {
75              HttpResponse res = new DefaultHttpResponse(HTTP_1_1, OK);
76  
77              ChannelBuffer content = WebSocketServerIndexPage.getContent(getWebSocketLocation(req));
78  
79              res.setHeader(CONTENT_TYPE, "text/html; charset=UTF-8");
80              setContentLength(res, content.readableBytes());
81  
82              res.setContent(content);
83              sendHttpResponse(ctx, req, res);
84              return;
85          } else if (req.getUri().equals("/favicon.ico")) {
86              HttpResponse res = new DefaultHttpResponse(HTTP_1_1, NOT_FOUND);
87              sendHttpResponse(ctx, req, res);
88              return;
89          }
90  
91          // Handshake
92          WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
93                  getWebSocketLocation(req), null, false);
94          handshaker = wsFactory.newHandshaker(req);
95          if (handshaker == null) {
96              wsFactory.sendUnsupportedWebSocketVersionResponse(ctx.getChannel());
97          } else {
98              handshaker.handshake(ctx.getChannel(), req).addListener(WebSocketServerHandshaker.HANDSHAKE_LISTENER);
99          }
100     }
101 
102     private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
103 
104         // Check for closing frame
105         if (frame instanceof CloseWebSocketFrame) {
106             handshaker.close(ctx.getChannel(), (CloseWebSocketFrame) frame);
107             return;
108         } else if (frame instanceof PingWebSocketFrame) {
109             ctx.getChannel().write(new PongWebSocketFrame(frame.getBinaryData()));
110             return;
111         } else if (!(frame instanceof TextWebSocketFrame)) {
112             throw new UnsupportedOperationException(String.format("%s frame types not supported", frame.getClass()
113                     .getName()));
114         }
115 
116         // Send the uppercase string back.
117         String request = ((TextWebSocketFrame) frame).getText();
118         if (logger.isDebugEnabled()) {
119             logger.debug(String.format("Channel %s received %s", ctx.getChannel().getId(), request));
120         }
121         ctx.getChannel().write(new TextWebSocketFrame(request.toUpperCase()));
122     }
123 
124     private static void sendHttpResponse(ChannelHandlerContext ctx, HttpRequest req, HttpResponse res) {
125         // Generate an error page if response status code is not OK (200).
126         if (res.getStatus().getCode() != 200) {
127             res.setContent(ChannelBuffers.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8));
128             setContentLength(res, res.getContent().readableBytes());
129         }
130 
131         // Send the response and close the connection if necessary.
132         ChannelFuture f = ctx.getChannel().write(res);
133         if (!isKeepAlive(req) || res.getStatus().getCode() != 200) {
134             f.addListener(ChannelFutureListener.CLOSE);
135         }
136     }
137 
138     @Override
139     public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
140         e.getCause().printStackTrace();
141         e.getChannel().close();
142     }
143 
144     private static String getWebSocketLocation(HttpRequest req) {
145         return "ws://" + req.getHeader(HOST) + WEBSOCKET_PATH;
146     }
147 }