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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.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  public class EchoClientHandler extends SimpleChannelUpstreamHandler {
    36
    37      private static final Logger logger = Logger.getLogger(
    38              EchoClientHandler.class.getName());
    39
    40      private final ChannelBuffer firstMessage;
    41      private final AtomicLong transferredBytes = new AtomicLong();
    42
    43      /**
    44       * Creates a client-side handler.
    45       */
    46      public EchoClientHandler(int firstMessageSize) {
    47          if (firstMessageSize <= 0) {
    48              throw new IllegalArgumentException(
    49                      "firstMessageSize: " + firstMessageSize);
    50          }
    51          firstMessage = ChannelBuffers.buffer(firstMessageSize);
    52          for (int i = 0; i < firstMessage.capacity(); i ++) {
    53              firstMessage.writeByte((byte) i);
    54          }
    55      }
    56
    57      public long getTransferredBytes() {
    58          return transferredBytes.get();
    59      }
    60
    61      @Override
    62      public void channelConnected(
    63              ChannelHandlerContext ctx, ChannelStateEvent e) {
    64          // Send the first message.  Server will not send anything here
    65          // because the firstMessage's capacity is 0.
    66          e.getChannel().write(firstMessage);
    67      }
    68
    69      @Override
    70      public void messageReceived(
    71              ChannelHandlerContext ctx, MessageEvent e) {
    72          // Send back the received message to the remote peer.
    73          transferredBytes.addAndGet(((ChannelBuffer) e.getMessage()).readableBytes());
    74          e.getChannel().write(e.getMessage());
    75      }
    76
    77      @Override
    78      public void exceptionCaught(
    79              ChannelHandlerContext ctx, ExceptionEvent e) {
    80          // Close the connection when an exception is raised.
    81          logger.log(
    82                  Level.WARNING,
    83                  "Unexpected exception from downstream.",
    84                  e.getCause());
    85          e.getChannel().close();
    86      }
    87  }