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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.telnet;
    17
    18  import java.net.InetAddress;
    19  import java.util.Date;
    20  import java.util.logging.Level;
    21  import java.util.logging.Logger;
    22
    23  import org.jboss.netty.channel.ChannelEvent;
    24  import org.jboss.netty.channel.ChannelFuture;
    25  import org.jboss.netty.channel.ChannelFutureListener;
    26  import org.jboss.netty.channel.ChannelHandlerContext;
    27  import org.jboss.netty.channel.ChannelStateEvent;
    28  import org.jboss.netty.channel.ExceptionEvent;
    29  import org.jboss.netty.channel.MessageEvent;
    30  import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
    31
    32  /**
    33   * Handles a server-side channel.
    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 TelnetServerHandler extends SimpleChannelUpstreamHandler {
    41
    42      private static final Logger logger = Logger.getLogger(
    43              TelnetServerHandler.class.getName());
    44
    45      @Override
    46      public void handleUpstream(
    47              ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
    48          if (e instanceof ChannelStateEvent) {
    49              logger.info(e.toString());
    50          }
    51          super.handleUpstream(ctx, e);
    52      }
    53
    54      @Override
    55      public void channelConnected(
    56              ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
    57          // Send greeting for a new connection.
    58          e.getChannel().write(
    59                  "Welcome to " + InetAddress.getLocalHost().getHostName() + "!\r\n");
    60          e.getChannel().write("It is " + new Date() + " now.\r\n");
    61      }
    62
    63      @Override
    64      public void messageReceived(
    65              ChannelHandlerContext ctx, MessageEvent e) {
    66
    67          // Cast to a String first.
    68          // We know it is a String because we put some codec in TelnetPipelineFactory.
    69          String request = (String) e.getMessage();
    70
    71          // Generate and write a response.
    72          String response;
    73          boolean close = false;
    74          if (request.length() == 0) {
    75              response = "Please type something.\r\n";
    76          } else if (request.toLowerCase().equals("bye")) {
    77              response = "Have a good day!\r\n";
    78              close = true;
    79          } else {
    80              response = "Did you say '" + request + "'?\r\n";
    81          }
    82
    83          // We do not need to write a ChannelBuffer here.
    84          // We know the encoder inserted at TelnetPipelineFactory will do the conversion.
    85          ChannelFuture future = e.getChannel().write(response);
    86
    87          // Close the connection after sending 'Have a good day!'
    88          // if the client has sent 'bye'.
    89          if (close) {
    90              future.addListener(ChannelFutureListener.CLOSE);
    91          }
    92      }
    93
    94      @Override
    95      public void exceptionCaught(
    96              ChannelHandlerContext ctx, ExceptionEvent e) {
    97          logger.log(
    98                  Level.WARNING,
    99                  "Unexpected exception from downstream.",
    100                 e.getCause());
    101         e.getChannel().close();
    102     }
    103 }