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 org.apache.commons.net.examples.nntp;
19
20 import java.io.IOException;
21
22 import org.apache.commons.net.nntp.NNTPClient;
23 import org.apache.commons.net.nntp.NewsgroupInfo;
24
25 /**
26 * This is a trivial example using the NNTP package to approximate the Unix newsgroups command. It merely connects to the specified news server and issues
27 * fetches the list of newsgroups stored by the server. On servers that store a lot of newsgroups, this command can take a very long time (listing upwards of
28 * 30,000 groups).
29 */
30
31 public final class ListNewsgroups {
32
33 public static void main(final String[] args) {
34 if (args.length < 1) {
35 System.err.println("Usage: newsgroups newsserver [pattern]");
36 return;
37 }
38
39 final NNTPClient client = new NNTPClient();
40 final String pattern = args.length >= 2 ? args[1] : "";
41
42 try {
43 client.connect(args[0]);
44
45 int j = 0;
46 try {
47 for (final String s : client.iterateNewsgroupListing(pattern)) {
48 j++;
49 System.out.println(s);
50 }
51 } catch (final IOException e1) {
52 e1.printStackTrace();
53 }
54 System.out.println(j);
55
56 j = 0;
57 for (final NewsgroupInfo n : client.iterateNewsgroups(pattern)) {
58 j++;
59 System.out.println(n.getNewsgroup());
60 }
61 System.out.println(j);
62 } catch (final IOException e) {
63 e.printStackTrace();
64 } finally {
65 try {
66 if (client.isConnected()) {
67 client.disconnect();
68 }
69 } catch (final IOException e) {
70 System.err.println("Error disconnecting from server.");
71 e.printStackTrace();
72 System.exit(1);
73 }
74 }
75
76 }
77
78 }