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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 io.netty.example.http.websocketx.server;
17  
18  import io.netty.buffer.ByteBuf;
19  import io.netty.buffer.Unpooled;
20  import io.netty.channel.ChannelFutureListener;
21  import io.netty.channel.ChannelHandlerContext;
22  import io.netty.channel.ChannelPipeline;
23  import io.netty.channel.SimpleChannelInboundHandler;
24  import io.netty.handler.codec.http.DefaultFullHttpResponse;
25  import io.netty.handler.codec.http.FullHttpRequest;
26  import io.netty.handler.codec.http.FullHttpResponse;
27  import io.netty.handler.codec.http.HttpHeaderNames;
28  import io.netty.handler.codec.http.HttpRequest;
29  import io.netty.handler.codec.http.HttpUtil;
30  import io.netty.handler.ssl.SslHandler;
31  import io.netty.util.CharsetUtil;
32  
33  import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_TYPE;
34  import static io.netty.handler.codec.http.HttpHeaderNames.CONNECTION;
35  import static io.netty.handler.codec.http.HttpHeaderValues.CLOSE;
36  import static io.netty.handler.codec.http.HttpHeaderValues.KEEP_ALIVE;
37  import static io.netty.handler.codec.http.HttpMethod.GET;
38  import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
39  import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN;
40  import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
41  import static io.netty.handler.codec.http.HttpResponseStatus.OK;
42  import static io.netty.handler.codec.http.HttpVersion.HTTP_1_0;
43  import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
44  
45  /**
46   * Outputs index page content.
47   */
48  public class WebSocketIndexPageHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
49  
50      private final String websocketPath;
51  
52      public WebSocketIndexPageHandler(String websocketPath) {
53          this.websocketPath = websocketPath;
54      }
55  
56      @Override
57      protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest req) throws Exception {
58          // Handle a bad request.
59          if (!req.decoderResult().isSuccess()) {
60              sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST, Unpooled.EMPTY_BUFFER));
61              return;
62          }
63  
64          // Allow only GET methods.
65          if (!GET.equals(req.method())) {
66              sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN, Unpooled.EMPTY_BUFFER));
67              return;
68          }
69  
70          // Send the index page
71          if ("/".equals(req.uri()) || "/index.html".equals(req.uri())) {
72              String webSocketLocation = getWebSocketLocation(ctx.pipeline(), req, websocketPath);
73              ByteBuf content = WebSocketServerIndexPage.getContent(webSocketLocation);
74              FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, OK, content);
75  
76              res.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
77              HttpUtil.setContentLength(res, content.readableBytes());
78  
79              sendHttpResponse(ctx, req, res);
80          } else {
81              sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, NOT_FOUND, Unpooled.EMPTY_BUFFER));
82          }
83      }
84  
85      @Override
86      public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
87          cause.printStackTrace();
88          ctx.close();
89      }
90  
91      private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) {
92          // Generate an error page if response getStatus code is not OK (200).
93          if (res.status().code() != 200) {
94              ByteBuf buf = Unpooled.copiedBuffer(res.status().toString(), CharsetUtil.UTF_8);
95              res.content().writeBytes(buf);
96              buf.release();
97              HttpUtil.setContentLength(res, res.content().readableBytes());
98          }
99  
100         // Send the response and close the connection if necessary.
101         if (!HttpUtil.isKeepAlive(req) || res.status().code() != 200) {
102             // Tell the client we're going to close the connection.
103             res.headers().set(CONNECTION, CLOSE);
104             ctx.writeAndFlush(res).addListener(ChannelFutureListener.CLOSE);
105         } else {
106             if (req.protocolVersion().equals(HTTP_1_0)) {
107                 res.headers().set(CONNECTION, KEEP_ALIVE);
108             }
109             ctx.writeAndFlush(res);
110         }
111     }
112 
113     private static String getWebSocketLocation(ChannelPipeline cp, HttpRequest req, String path) {
114         String protocol = "ws";
115         if (cp.get(SslHandler.class) != null) {
116             // SSL in use so use Secure WebSockets
117             protocol = "wss";
118         }
119         return protocol + "://" + req.headers().get(HttpHeaderNames.HOST) + path;
120     }
121 }