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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 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.handler.ssl.SslContext;
25  import io.netty.handler.ssl.SslContextBuilder;
26  import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
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;
43          if (SSL) {
44              sslCtx = SslContextBuilder.forClient()
45                  .trustManager(InsecureTrustManagerFactory.INSTANCE).build();
46          } else {
47              sslCtx = null;
48          }
49  
50          EventLoopGroup group = new NioEventLoopGroup();
51          try {
52              Bootstrap b = new Bootstrap();
53              b.group(group)
54               .channel(NioSocketChannel.class)
55               .handler(new TelnetClientInitializer(sslCtx));
56  
57              // Start the connection attempt.
58              Channel ch = b.connect(HOST, PORT).sync().channel();
59  
60              // Read commands from the stdin.
61              ChannelFuture lastWriteFuture = null;
62              BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
63              for (;;) {
64                  String line = in.readLine();
65                  if (line == null) {
66                      break;
67                  }
68  
69                  // Sends the received line to the server.
70                  lastWriteFuture = ch.writeAndFlush(line + "\r\n");
71  
72                  // If user typed the 'bye' command, wait until the server closes
73                  // the connection.
74                  if ("bye".equals(line.toLowerCase())) {
75                      ch.closeFuture().sync();
76                      break;
77                  }
78              }
79  
80              // Wait until all messages are flushed before closing the channel.
81              if (lastWriteFuture != null) {
82                  lastWriteFuture.sync();
83              }
84          } finally {
85              group.shutdownGracefully();
86          }
87      }
88  }