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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.netty5.example.telnet;
17  
18  import io.netty5.bootstrap.Bootstrap;
19  import io.netty5.channel.Channel;
20  import io.netty5.channel.EventLoopGroup;
21  import io.netty5.channel.MultithreadEventLoopGroup;
22  import io.netty5.channel.nio.NioHandler;
23  import io.netty5.channel.socket.nio.NioSocketChannel;
24  import io.netty5.handler.ssl.SslContext;
25  import io.netty5.handler.ssl.SslContextBuilder;
26  import io.netty5.handler.ssl.util.InsecureTrustManagerFactory;
27  import io.netty5.util.concurrent.Future;
28  
29  import java.io.BufferedReader;
30  import java.io.InputStreamReader;
31  
32  /**
33   * Simplistic telnet client.
34   */
35  public final class TelnetClient {
36  
37      static final boolean SSL = System.getProperty("ssl") != null;
38      static final String HOST = System.getProperty("host", "127.0.0.1");
39      static final int PORT = Integer.parseInt(System.getProperty("port", SSL? "8992" : "8023"));
40  
41      public static void main(String[] args) throws Exception {
42          // Configure SSL.
43          final SslContext sslCtx;
44          if (SSL) {
45              sslCtx = SslContextBuilder.forClient()
46                  .trustManager(InsecureTrustManagerFactory.INSTANCE).build();
47          } else {
48              sslCtx = null;
49          }
50  
51          EventLoopGroup group = new MultithreadEventLoopGroup(NioHandler.newFactory());
52          try {
53              Bootstrap b = new Bootstrap();
54              b.group(group)
55               .channel(NioSocketChannel.class)
56               .handler(new TelnetClientInitializer(sslCtx));
57  
58              // Start the connection attempt.
59              Channel ch = b.connect(HOST, PORT).asStage().get();
60  
61              // Read commands from the stdin.
62              Future<Void> lastWriteFuture = null;
63              BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
64              for (;;) {
65                  String line = in.readLine();
66                  if (line == null) {
67                      break;
68                  }
69  
70                  // Sends the received line to the server.
71                  lastWriteFuture = ch.writeAndFlush(line + "\r\n");
72  
73                  // If user typed the 'bye' command, wait until the server closes
74                  // the connection.
75                  if ("bye".equalsIgnoreCase(line)) {
76                      ch.closeFuture().asStage().sync();
77                      break;
78                  }
79              }
80  
81              // Wait until all messages are flushed before closing the channel.
82              if (lastWriteFuture != null) {
83                  lastWriteFuture.asStage().sync();
84              }
85          } finally {
86              group.shutdownGracefully();
87          }
88      }
89  }