Commons Net example source code file (Article.java)

This example Commons Net source code file (Article.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Net tags/keywords

arraylist, article, article, deprecated, deprecated, e, eclipse, override, re, string, string, threadable, threadable, useful, util

The Commons Net Article.java source code

/*
 * 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 org.apache.commons.net.nntp;

import java.util.ArrayList;

/**
 * This is a class that contains the basic state needed for message retrieval and threading.
 * With thanks to Jamie  Zawinski <jwz@jwz.org>
 * @author rwinston <rwinston@apache.org>
 */
public class Article implements Threadable {
    private long articleNumber;
    private String subject;
    private String date;
    private String articleId;
    private String simplifiedSubject;
    private String from;
    private ArrayList<String> references;
    private boolean isReply = false;

    public Article kid, next;

    public Article() {
        articleNumber = -1; // isDummy
    }

    /**
     * Adds a message-id to the list of messages that this message references (i.e. replies to)
     * @param msgId
     */
    public void addReference(String msgId) {
        if (msgId == null || msgId.length() == 0) {
            return;
        }
        if (references == null) {
            references = new ArrayList<String>();
        }
        isReply = true;
        for(String s : msgId.split(" ")) {
            references.add(s);
        }
    }

    /**
     * Returns the MessageId references as an array of Strings
     * @return an array of message-ids
     */
    public String[] getReferences() {
        if (references == null) {
            return new String[0];
        }
        return references.toArray(new String[references.size()]);
    }

    /**
     * Attempts to parse the subject line for some typical reply signatures, and strip them out
     *
     */
    private void simplifySubject() {
            int start = 0;
            String subject = getSubject();
            int len = subject.length();

            boolean done = false;

            while (!done) {
                done = true;

                // skip whitespace
                // "Re: " breaks this
                while (start < len && subject.charAt(start) == ' ') {
                    start++;
                }

                if (start < (len - 2)
                    && (subject.charAt(start) == 'r' || subject.charAt(start) == 'R')
                    && (subject.charAt(start + 1) == 'e' || subject.charAt(start + 1) == 'E')) {

                    if (subject.charAt(start + 2) == ':') {
                        start += 3; // Skip "Re:"
                        done = false;
                    } else if (
                        start < (len - 2)
                        &&
                        (subject.charAt(start + 2) == '[' || subject.charAt(start + 2) == '(')) {

                        int i = start + 3;

                        while (i < len && subject.charAt(i) >= '0' && subject.charAt(i) <= '9')
                            i++;

                        if (i < (len - 1)
                            && (subject.charAt(i) == ']' || subject.charAt(i) == ')')
                            && subject.charAt(i + 1) == ':') {
                            start = i + 2;
                            done = false;
                        }
                    }
                }

                if ("(no subject)".equals(simplifiedSubject))
                    simplifiedSubject = "";

                int end = len;

                while (end > start && subject.charAt(end - 1) < ' ')
                    end--;

                if (start == 0 && end == len)
                    simplifiedSubject = subject;
                else
                    simplifiedSubject = subject.substring(start, end);
            }
        }

    /**
     * Recursive method that traverses a pre-threaded graph (or tree)
     * of connected Article objects and prints them out.
     * @param article the root of the article 'tree'
     * @param depth the current tree depth
     */
    public static void printThread(Article article, int depth) {
            for (int i = 0; i < depth; ++i)
                System.out.print("==>");
            System.out.println(article.getSubject() + "\t" + article.getFrom());
            if (article.kid != null)
                printThread(article.kid, depth + 1);
            if (article.next != null)
                printThread(article.next, depth);
    }

    public String getArticleId() {
        return articleId;
    }

    public long getArticleNumberLong() {
        return articleNumber;
    }

    public String getDate() {
        return date;
    }

    public String getFrom() {
        return from;
    }

    public String getSubject() {
        return subject;
    }

    public void setArticleId(String string) {
        articleId = string;
    }

    public void setArticleNumber(long l) {
        articleNumber = l;
    }

    public void setDate(String string) {
        date = string;
    }

    public void setFrom(String string) {
        from = string;
    }

    public void setSubject(String string) {
        subject = string;
    }


    public boolean isDummy() {
        return (articleNumber == -1);
    }

    public String messageThreadId() {
        return articleId;
    }

    public String[] messageThreadReferences() {
        return getReferences();
    }

    public String simplifiedSubject() {
        if(simplifiedSubject == null)
            simplifySubject();
        return simplifiedSubject;
    }


    public boolean subjectIsReply() {
        return isReply;
    }


    public void setChild(Threadable child) {
        this.kid = (Article) child;
        flushSubjectCache();
    }

    private void flushSubjectCache() {
        simplifiedSubject = null;
    }


    public void setNext(Threadable next) {
        this.next = (Article)next;
        flushSubjectCache();
    }


    public Threadable makeDummy() {
        return new Article();
    }

    @Override
    public String toString(){ // Useful for Eclipse debugging
        return articleNumber + " " +articleId + " " + subject;
    }

    // DEPRECATED METHODS - for API compatibility only - DO NOT USE

    @Deprecated
    public int getArticleNumber() {
        return (int) articleNumber;
    }

    @Deprecated
    public void setArticleNumber(int a) {
        articleNumber = a;
    }
    @Deprecated

    public void addHeaderField(String name, String val) {
    }

}