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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.echo;
    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.buffer.ChannelBuffers;
    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   * Handler implementation for the echo client.  It initiates the ping-pong
    32   * traffic between the echo client and server by sending the first message to
    33   * the server.
    34   *
    35   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
    36   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
    37   *
    38   * @version $Rev: 2121 $, $Date: 2010-02-02 09:38:07 +0900 (Tue, 02 Feb 2010) $
    39   */
    40  public class EchoClientHandler extends SimpleChannelUpstreamHandler {
    41
    42      private static final Logger logger = Logger.getLogger(
    43              EchoClientHandler.class.getName());
    44
    45      private final ChannelBuffer firstMessage;
    46      private final AtomicLong transferredBytes = new AtomicLong();
    47
    48      /**
    49       * Creates a client-side handler.
    50       */
    51      public EchoClientHandler(int firstMessageSize) {
    52          if (firstMessageSize <= 0) {
    53              throw new IllegalArgumentException(
    54                      "firstMessageSize: " + firstMessageSize);
    55          }
    56          firstMessage = ChannelBuffers.buffer(firstMessageSize);
    57          for (int i = 0; i < firstMessage.capacity(); i ++) {
    58              firstMessage.writeByte((byte) i);
    59          }
    60      }
    61
    62      public long getTransferredBytes() {
    63          return transferredBytes.get();
    64      }
    65
    66      @Override
    67      public void channelConnected(
    68              ChannelHandlerContext ctx, ChannelStateEvent e) {
    69          // Send the first message.  Server will not send anything here
    70          // because the firstMessage's capacity is 0.
    71          e.getChannel().write(firstMessage);
    72      }
    73
    74      @Override
    75      public void messageReceived(
    76              ChannelHandlerContext ctx, MessageEvent e) {
    77          // Send back the received message to the remote peer.
    78          transferredBytes.addAndGet(((ChannelBuffer) e.getMessage()).readableBytes());
    79          e.getChannel().write(e.getMessage());
    80      }
    81
    82      @Override
    83      public void exceptionCaught(
    84              ChannelHandlerContext ctx, ExceptionEvent e) {
    85          // Close the connection when an exception is raised.
    86          logger.log(
    87                  Level.WARNING,
    88                  "Unexpected exception from downstream.",
    89                  e.getCause());
    90          e.getChannel().close();
    91      }
    92  }