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1   /*
2    * Copyright 2016 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    *   https://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  
17  package io.netty.example.http2.helloworld.multiplex.server;
18  
19  import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
20  
21  import io.netty.channel.ChannelHandlerContext;
22  import io.netty.channel.ChannelInboundHandlerAdapter;
23  import io.netty.channel.ChannelInitializer;
24  import io.netty.channel.ChannelPipeline;
25  import io.netty.channel.SimpleChannelInboundHandler;
26  import io.netty.channel.socket.SocketChannel;
27  import io.netty.example.http2.helloworld.server.HelloWorldHttp1Handler;
28  import io.netty.handler.codec.http.HttpMessage;
29  import io.netty.handler.codec.http.HttpObjectAggregator;
30  import io.netty.handler.codec.http.HttpServerCodec;
31  import io.netty.handler.codec.http.HttpServerUpgradeHandler;
32  import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodec;
33  import io.netty.handler.codec.http.HttpServerUpgradeHandler.UpgradeCodecFactory;
34  import io.netty.handler.codec.http2.Http2FrameCodecBuilder;
35  import io.netty.handler.codec.http2.Http2CodecUtil;
36  import io.netty.handler.codec.http2.Http2MultiplexHandler;
37  import io.netty.handler.codec.http2.Http2ServerUpgradeCodec;
38  import io.netty.handler.ssl.SslContext;
39  import io.netty.util.AsciiString;
40  import io.netty.util.ReferenceCountUtil;
41  
42  /**
43   * Sets up the Netty pipeline for the example server. Depending on the endpoint config, sets up the
44   * pipeline for NPN or cleartext HTTP upgrade to HTTP/2.
45   */
46  public class Http2ServerInitializer extends ChannelInitializer<SocketChannel> {
47  
48      private static final UpgradeCodecFactory upgradeCodecFactory = new UpgradeCodecFactory() {
49          @Override
50          public UpgradeCodec newUpgradeCodec(CharSequence protocol) {
51              if (AsciiString.contentEquals(Http2CodecUtil.HTTP_UPGRADE_PROTOCOL_NAME, protocol)) {
52                  return new Http2ServerUpgradeCodec(
53                          Http2FrameCodecBuilder.forServer().build(),
54                          new Http2MultiplexHandler(new HelloWorldHttp2Handler()));
55              } else {
56                  return null;
57              }
58          }
59      };
60  
61      private final SslContext sslCtx;
62      private final int maxHttpContentLength;
63  
64      public Http2ServerInitializer(SslContext sslCtx) {
65          this(sslCtx, 16 * 1024);
66      }
67  
68      public Http2ServerInitializer(SslContext sslCtx, int maxHttpContentLength) {
69          this.sslCtx = sslCtx;
70          this.maxHttpContentLength = checkPositiveOrZero(maxHttpContentLength, "maxHttpContentLength");
71      }
72  
73      @Override
74      public void initChannel(SocketChannel ch) {
75          if (sslCtx != null) {
76              configureSsl(ch);
77          } else {
78              configureClearText(ch);
79          }
80      }
81  
82      /**
83       * Configure the pipeline for TLS NPN negotiation to HTTP/2.
84       */
85      private void configureSsl(SocketChannel ch) {
86          ch.pipeline().addLast(sslCtx.newHandler(ch.alloc()), new Http2OrHttpHandler());
87      }
88  
89      /**
90       * Configure the pipeline for a cleartext upgrade from HTTP to HTTP/2.0
91       */
92      private void configureClearText(SocketChannel ch) {
93          final ChannelPipeline p = ch.pipeline();
94          final HttpServerCodec sourceCodec = new HttpServerCodec();
95  
96          p.addLast(sourceCodec);
97          p.addLast(new HttpServerUpgradeHandler(sourceCodec, upgradeCodecFactory));
98          p.addLast(new SimpleChannelInboundHandler<HttpMessage>() {
99              @Override
100             protected void channelRead0(ChannelHandlerContext ctx, HttpMessage msg) throws Exception {
101                 // If this handler is hit then no upgrade has been attempted and the client is just talking HTTP.
102                 System.err.println("Directly talking: " + msg.protocolVersion() + " (no upgrade was attempted)");
103                 ChannelPipeline pipeline = ctx.pipeline();
104                 pipeline.addAfter(ctx.name(), null, new HelloWorldHttp1Handler("Direct. No Upgrade Attempted."));
105                 pipeline.replace(this, null, new HttpObjectAggregator(maxHttpContentLength));
106                 ctx.fireChannelRead(ReferenceCountUtil.retain(msg));
107             }
108         });
109 
110         p.addLast(new UserEventLogger());
111     }
112 
113     /**
114      * Class that logs any User Events triggered on this channel.
115      */
116     private static class UserEventLogger extends ChannelInboundHandlerAdapter {
117         @Override
118         public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
119             System.out.println("User Event Triggered: " + evt);
120             ctx.fireUserEventTriggered(evt);
121         }
122     }
123 }