NNTPUtils.java

/*
 * 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.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.StringTokenizer;

import org.apache.commons.net.io.DotTerminatedMessageReader;
import org.apache.commons.net.nntp.Article;
import org.apache.commons.net.nntp.NNTPClient;

/**
 * 
 * Some convenience methods for NNTP example classes.
 * 
 * @author Rory Winston <rwinston@checkfree.com>
 */
public class NNTPUtils {

    /**
     * Given an {@link NNTPClient} instance, and an integer range of messages, return 
     * an array of {@link Article} instances.
     * @param client 
     * @param lowArticleNumber
     * @param highArticleNumber
     * @return Article[] An array of Article
     * @throws IOException
     */
    public  static Article[] getArticleInfo(NNTPClient client, int lowArticleNumber, int highArticleNumber)
            throws IOException {
            Reader reader = null;
            Article[] articles = null;
            reader =
                (DotTerminatedMessageReader) client.retrieveArticleInfo(
                    lowArticleNumber,
                    highArticleNumber);

            if (reader != null) {
                String theInfo = readerToString(reader);
                StringTokenizer st = new StringTokenizer(theInfo, "\n");

                // Extract the article information
                // Mandatory format (from NNTP RFC 2980) is :
                // Subject\tAuthor\tDate\tID\tReference(s)\tByte Count\tLine Count

                int count = st.countTokens();
                articles = new Article[count];
                int index = 0;

                while (st.hasMoreTokens()) {
                    StringTokenizer stt = new StringTokenizer(st.nextToken(), "\t");
                    Article article = new Article();
                    article.setArticleNumber(Integer.parseInt(stt.nextToken()));
                    article.setSubject(stt.nextToken());
                    article.setFrom(stt.nextToken());
                    article.setDate(stt.nextToken());
                    article.setArticleId(stt.nextToken());
                    article.addHeaderField("References", stt.nextToken());
                    articles[index++] = article;
                }
            } else {
                return null;
            }

            return articles;
        }
        
    
    /**
     * Convert a {@link Reader} instance to a String
     * @param reader The Reader instance
     * @return String
     */
    public static String readerToString(Reader reader) {
        String temp = null;
        StringBuffer sb = null;
        BufferedReader bufReader = new BufferedReader(reader);

        sb = new StringBuffer();
        try {
            temp = bufReader.readLine();
            while (temp != null) {
                sb.append(temp);
                sb.append("\n");
                temp = bufReader.readLine();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        return sb.toString();
    }
}