001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package examples.nntp;
019
020import java.io.IOException;
021import org.apache.commons.net.nntp.NNTPClient;
022import org.apache.commons.net.nntp.NewsgroupInfo;
023
024/***
025 * This is a trivial example using the NNTP package to approximate the
026 * Unix newsgroups command.  It merely connects to the specified news
027 * server and issues fetches the list of newsgroups stored by the server.
028 * On servers that store a lot of newsgroups, this command can take a very
029 * long time (listing upwards of 30,000 groups).
030 ***/
031
032public final class ListNewsgroups
033{
034
035    public static void main(String[] args)
036    {
037        if (args.length < 1)
038        {
039            System.err.println("Usage: newsgroups newsserver [pattern]");
040            return;
041        }
042
043        NNTPClient client = new NNTPClient();
044        String pattern = args.length >= 2 ? args[1] : "";
045
046        try
047        {
048            client.connect(args[0]);
049
050            int j = 0;
051            try {
052                for(String s : client.iterateNewsgroupListing(pattern)) {
053                    j++;
054                    System.out.println(s);
055                }
056            } catch (IOException e1) {
057                e1.printStackTrace();
058            }
059            System.out.println(j);
060
061            j = 0;
062            for(NewsgroupInfo n : client.iterateNewsgroups(pattern)) {
063                j++;
064                System.out.println(n.getNewsgroup());
065            }
066            System.out.println(j);
067        }
068        catch (IOException e)
069        {
070            e.printStackTrace();
071        }
072        finally
073        {
074            try
075            {
076                if (client.isConnected()) {
077                    client.disconnect();
078                }
079            }
080            catch (IOException e)
081            {
082                System.err.println("Error disconnecting from server.");
083                e.printStackTrace();
084                System.exit(1);
085            }
086        }
087
088    }
089
090}
091
092