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