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1   /*
2    * Copyright 2009 Red Hat, Inc.
3    *
4    * Red Hat licenses this file to you under the Apache License, version 2.0
5    * (the "License"); you may not use this file except in compliance with the
6    * 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.discard;
17  
18  import java.util.concurrent.atomic.AtomicLong;
19  import java.util.logging.Level;
20  import java.util.logging.Logger;
21  
22  import org.jboss.netty.buffer.ChannelBuffer;
23  import org.jboss.netty.channel.ChannelEvent;
24  import org.jboss.netty.channel.ChannelHandlerContext;
25  import org.jboss.netty.channel.ChannelStateEvent;
26  import org.jboss.netty.channel.ExceptionEvent;
27  import org.jboss.netty.channel.MessageEvent;
28  import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
29  
30  /**
31   * Handles a server-side channel.
32   *
33   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
34   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
35   *
36   * @version $Rev: 2121 $, $Date: 2010-02-02 09:38:07 +0900 (Tue, 02 Feb 2010) $
37   */
38  public class DiscardServerHandler extends SimpleChannelUpstreamHandler {
39  
40      private static final Logger logger = Logger.getLogger(
41              DiscardServerHandler.class.getName());
42  
43      private final AtomicLong transferredBytes = new AtomicLong();
44  
45      public long getTransferredBytes() {
46          return transferredBytes.get();
47      }
48  
49      @Override
50      public void handleUpstream(ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
51          if (e instanceof ChannelStateEvent) {
52              logger.info(e.toString());
53          }
54  
55          // Let SimpleChannelHandler call actual event handler methods below.
56          super.handleUpstream(ctx, e);
57      }
58  
59      @Override
60      public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
61          // Discard received data silently by doing nothing.
62          transferredBytes.addAndGet(((ChannelBuffer) e.getMessage()).readableBytes());
63      }
64  
65      @Override
66      public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
67          // Close the connection when an exception is raised.
68          logger.log(
69                  Level.WARNING,
70                  "Unexpected exception from downstream.",
71                  e.getCause());
72          e.getChannel().close();
73      }
74  }