Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package examples.nntp; import java.io.IOException; import org.apache.commons.net.nntp.NNTPClient; import org.apache.commons.net.nntp.NewsgroupInfo; /*** * 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 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 30,000 groups). * <p> ***/ public final class ListNewsgroups { public static void main(String[] args) { if (args.length < 1) { System.err.println("Usage: newsgroups newsserver [pattern]"); return; } NNTPClient client = new NNTPClient(); String pattern = args.length >= 2 ? args[1] : ""; try { client.connect(args[0]); int j = 0; try { for (String s : client.iterateNewsgroupListing(pattern)) { j++; System.out.println(s); } } catch (IOException e1) { e1.printStackTrace(); } System.out.println(j); j = 0; for (NewsgroupInfo n : client.iterateNewsgroups(pattern)) { j++; System.out.println(n.getNewsgroup()); } System.out.println(j); } catch (IOException e) { e.printStackTrace(); } finally { try { if (client.isConnected()) { client.disconnect(); } } catch (IOException e) { System.err.println("Error disconnecting from server."); e.printStackTrace(); System.exit(1); } } } }