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 * <p>
031 ***/
032
033public final class newsgroups
034{
035
036    public final static void main(String[] args)
037    {
038        NNTPClient client;
039        NewsgroupInfo[] list;
040
041        if (args.length < 1)
042        {
043            System.err.println("Usage: newsgroups newsserver");
044            System.exit(1);
045        }
046
047        client = new NNTPClient();
048
049        try
050        {
051            client.connect(args[0]);
052
053            list = client.listNewsgroups();
054
055            if (list != null)
056            {
057                for (int i = 0; i < list.length; i++)
058                    System.out.println(list[i].getNewsgroup());
059            }
060            else
061            {
062                System.err.println("LIST command failed.");
063                System.err.println("Server reply: " + client.getReplyString());
064            }
065        }
066        catch (IOException e)
067        {
068            e.printStackTrace();
069        }
070        finally
071        {
072            try
073            {
074                if (client.isConnected())
075                    client.disconnect();
076            }
077            catch (IOException e)
078            {
079                System.err.println("Error disconnecting from server.");
080                e.printStackTrace();
081                System.exit(1);
082            }
083        }
084
085    }
086
087}
088
089