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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    *   https://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 io.netty.example.telnet;
17  
18  import io.netty.bootstrap.Bootstrap;
19  import io.netty.channel.Channel;
20  import io.netty.channel.ChannelFuture;
21  import io.netty.channel.EventLoopGroup;
22  import io.netty.channel.MultiThreadIoEventLoopGroup;
23  import io.netty.channel.nio.NioIoHandler;
24  import io.netty.channel.socket.nio.NioSocketChannel;
25  import io.netty.example.util.ServerUtil;
26  import io.netty.handler.ssl.SslContext;
27  
28  import java.io.BufferedReader;
29  import java.io.InputStreamReader;
30  
31  /**
32   * Simplistic telnet client.
33   */
34  public final class TelnetClient {
35  
36      static final boolean SSL = System.getProperty("ssl") != null;
37      static final String HOST = System.getProperty("host", "127.0.0.1");
38      static final int PORT = Integer.parseInt(System.getProperty("port", SSL? "8992" : "8023"));
39  
40      public static void main(String[] args) throws Exception {
41          // Configure SSL.
42          final SslContext sslCtx = ServerUtil.buildSslContext();
43  
44          EventLoopGroup group = new MultiThreadIoEventLoopGroup(NioIoHandler.newFactory());
45          try {
46              Bootstrap b = new Bootstrap();
47              b.group(group)
48               .channel(NioSocketChannel.class)
49               .handler(new TelnetClientInitializer(sslCtx));
50  
51              // Start the connection attempt.
52              Channel ch = b.connect(HOST, PORT).sync().channel();
53  
54              // Read commands from the stdin.
55              ChannelFuture lastWriteFuture = null;
56              BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
57              for (;;) {
58                  String line = in.readLine();
59                  if (line == null) {
60                      break;
61                  }
62  
63                  // Sends the received line to the server.
64                  lastWriteFuture = ch.writeAndFlush(line + "\r\n");
65  
66                  // If user typed the 'bye' command, wait until the server closes
67                  // the connection.
68                  if ("bye".equals(line.toLowerCase())) {
69                      ch.closeFuture().sync();
70                      break;
71                  }
72              }
73  
74              // Wait until all messages are flushed before closing the channel.
75              if (lastWriteFuture != null) {
76                  lastWriteFuture.sync();
77              }
78          } finally {
79              group.shutdownGracefully();
80          }
81      }
82  }