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1   /*
2    * Copyright 2001-2005 The Apache Software Foundation
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * 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,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package examples.nntp;
17  
18  import java.io.IOException;
19  import org.apache.commons.net.nntp.NNTPClient;
20  import org.apache.commons.net.nntp.NewsgroupInfo;
21  
22  /***
23   * This is a trivial example using the NNTP package to approximate the
24   * Unix newsgroups command.  It merely connects to the specified news
25   * server and issues fetches the list of newsgroups stored by the server.
26   * On servers that store a lot of newsgroups, this command can take a very
27   * long time (listing upwards of 30,000 groups).
28   * <p>
29   ***/
30  
31  public final class newsgroups
32  {
33  
34      public final static void main(String[] args)
35      {
36          NNTPClient client;
37          NewsgroupInfo[] list;
38  
39          if (args.length < 1)
40          {
41              System.err.println("Usage: newsgroups newsserver");
42              System.exit(1);
43          }
44  
45          client = new NNTPClient();
46  
47          try
48          {
49              client.connect(args[0]);
50  
51              list = client.listNewsgroups();
52  
53              if (list != null)
54              {
55                  for (int i = 0; i < list.length; i++)
56                      System.out.println(list[i].getNewsgroup());
57              }
58              else
59              {
60                  System.err.println("LIST command failed.");
61                  System.err.println("Server reply: " + client.getReplyString());
62              }
63          }
64          catch (IOException e)
65          {
66              e.printStackTrace();
67          }
68          finally
69          {
70              try
71              {
72                  if (client.isConnected())
73                      client.disconnect();
74              }
75              catch (IOException e)
76              {
77                  System.err.println("Error disconnecting from server.");
78                  e.printStackTrace();
79                  System.exit(1);
80              }
81          }
82  
83      }
84  
85  }
86  
87