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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package examples.nntp;
19  
20  import java.io.IOException;
21  import org.apache.commons.net.nntp.NNTPClient;
22  import org.apache.commons.net.nntp.NewsgroupInfo;
23  
24  /***
25   * This is a trivial example using the NNTP package to approximate the
26   * Unix newsgroups command.  It merely connects to the specified news
27   * server and issues fetches the list of newsgroups stored by the server.
28   * On servers that store a lot of newsgroups, this command can take a very
29   * long time (listing upwards of 30,000 groups).
30   * <p>
31   ***/
32  
33  public final class ListNewsgroups
34  {
35  
36      public static void main(String[] args)
37      {
38          if (args.length < 1)
39          {
40              System.err.println("Usage: newsgroups newsserver [pattern]");
41              return;
42          }
43  
44          NNTPClient client = new NNTPClient();
45          String pattern = args.length >= 2 ? args[1] : "";
46  
47          try
48          {
49              client.connect(args[0]);
50  
51              int j = 0;
52              try {
53                  for(String s : client.iterateNewsgroupListing(pattern)) {
54                      j++;
55                      System.out.println(s);
56                  }
57              } catch (IOException e1) {
58                  e1.printStackTrace();
59              }
60              System.out.println(j);
61  
62              j = 0;
63              for(NewsgroupInfo n : client.iterateNewsgroups(pattern)) {
64                  j++;
65                  System.out.println(n.getNewsgroup());
66              }
67              System.out.println(j);
68          }
69          catch (IOException e)
70          {
71              e.printStackTrace();
72          }
73          finally
74          {
75              try
76              {
77                  if (client.isConnected()) {
78                      client.disconnect();
79                  }
80              }
81              catch (IOException e)
82              {
83                  System.err.println("Error disconnecting from server.");
84                  e.printStackTrace();
85                  System.exit(1);
86              }
87          }
88  
89      }
90  
91  }
92  
93