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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.uptime;
    17
    18  import java.net.ConnectException;
    19  import java.net.InetSocketAddress;
    20  import java.util.concurrent.TimeUnit;
    21
    22  import org.jboss.netty.bootstrap.ClientBootstrap;
    23  import org.jboss.netty.channel.ChannelHandlerContext;
    24  import org.jboss.netty.channel.ChannelStateEvent;
    25  import org.jboss.netty.channel.ExceptionEvent;
    26  import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
    27  import org.jboss.netty.handler.timeout.ReadTimeoutException;
    28  import org.jboss.netty.util.Timeout;
    29  import org.jboss.netty.util.Timer;
    30  import org.jboss.netty.util.TimerTask;
    31
    32  /**
    33   * Keep reconnecting to the server while printing out the current uptime and
    34   * connection attempt status.
    35   */
    36  public class UptimeClientHandler extends SimpleChannelUpstreamHandler {
    37
    38      final ClientBootstrap bootstrap;
    39      private final Timer timer;
    40      private long startTime = -1;
    41
    42      public UptimeClientHandler(ClientBootstrap bootstrap, Timer timer) {
    43          this.bootstrap = bootstrap;
    44          this.timer = timer;
    45      }
    46
    47      InetSocketAddress getRemoteAddress() {
    48          return (InetSocketAddress) bootstrap.getOption("remoteAddress");
    49      }
    50
    51      @Override
    52      public void channelDisconnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
    53          println("Disconnected from: " + getRemoteAddress());
    54      }
    55
    56      @Override
    57      public void channelClosed(ChannelHandlerContext ctx, ChannelStateEvent e) {
    58          println("Sleeping for: " + UptimeClient.RECONNECT_DELAY + "s");
    59          timer.newTimeout(new TimerTask() {
    60              public void run(Timeout timeout) throws Exception {
    61                  println("Reconnecting to: " + getRemoteAddress());
    62                  bootstrap.connect();
    63              }
    64          }, UptimeClient.RECONNECT_DELAY, TimeUnit.SECONDS);
    65      }
    66
    67      @Override
    68      public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
    69          if (startTime < 0) {
    70              startTime = System.currentTimeMillis();
    71          }
    72
    73          println("Connected to: " + getRemoteAddress());
    74      }
    75
    76      @Override
    77      public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
    78          Throwable cause = e.getCause();
    79          if (cause instanceof ConnectException) {
    80              startTime = -1;
    81              println("Failed to connect: " + cause.getMessage());
    82          }
    83          if (cause instanceof ReadTimeoutException) {
    84              // The connection was OK but there was no traffic for last period.
    85              println("Disconnecting due to no inbound traffic");
    86          } else {
    87              cause.printStackTrace();
    88          }
    89          ctx.getChannel().close();
    90      }
    91
    92      void println(String msg) {
    93          if (startTime < 0) {
    94              System.err.format("[SERVER IS DOWN] %s%n", msg);
    95          } else {
    96              System.err.format("[UPTIME: %5ds] %s%n", (System.currentTimeMillis() - startTime) / 1000, msg);
    97          }
    98      }
    99  }