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