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    
018    package examples.nntp;
019    
020    import java.io.IOException;
021    import org.apache.commons.net.nntp.NNTPClient;
022    import 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    
033    public 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