forumdaoxml.java

一个功能较为完善的论坛

/*
 * XP Forum
 *
 * Copyright (c) 2002-2003 RedSoft Group.  All rights reserved.
 *
 */
package org.redsoft.forum.dao.xml;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.redsoft.forum.dao.ForumDAO;
import org.redsoft.forum.web.Forum;

/**
 * AccountDAO's implmentation for xml
 *
 * @@author <a href="mailto:[e-mail]">cinc</a>
 *
 * @@version $Id: ForumDAOxml.java,v 1.1.1.1 2003/07/08 08:25:16 cinc Exp $
 */
public class ForumDAOxml implements ForumDAO {
    Forum[] forums;

    /**
     * Constructor, read forum infomation from forum.xml, and save them to
     * array forums[]
     *
     * @param filename        full filename of forum.xml
     */
    public ForumDAOxml( String filename ){
        int i;
        File xmlFile = new File( filename );
        ArrayList forumList = new ArrayList();
        Document doc = null;
        try{
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            // validate xml file by parser
            // that is: use a dtd file to validate the xml file
            dbf.setValidating(true);
            DocumentBuilder db = dbf.newDocumentBuilder();
            doc = db.parse( xmlFile );

            Element root = doc.getDocumentElement();
            root.normalize();
            NodeList nodes = root.getChildNodes();

            for (i=0; i<nodes.getLength() ; i++){
                Node node = nodes.item(i);
                if (node.getNodeName().equals( "forum" )){
                    forumList.add( parseForumNode(node) );
                }
            }

            // convert ArrayList to Array
            forums = new Forum[forumList.size()];
            for (i=0; i<forumList.size(); i++){
                forums[i] = (Forum)forumList.get(i);
            }
        }catch(Exception e){
            System.out.println ("Error reading forums.xml: " + e);
        }
    }

    /**
     * Read id, name, desc from this node
     */
    protected Forum parseForumNode( Node forum ){
        int id = 0;
        String name = null;
        String desc = null;
        String property, value;
        NodeList nodes = forum.getChildNodes();
        for (int i=0; i<nodes.getLength() ; i++){
            Node node = nodes.item(i);
            if (node.getNodeName().equals( "#text" )){
                continue;
            }
            property = node.getNodeName();
            value = node.getFirstChild().getNodeValue();
            if ( property.equals("id") ){
                id = Integer.parseInt( value );
            }else if ( property.equals("name") ){
                name = value;
            }else if ( property.equals("desc") ){
                desc = value;
            }
//            System.out.println(node.getNodeName() + ":" + node.getFirstChild().getNodeValue());
        }
        return new Forum( id, name, desc );
    }

    /**
     * Return the forum given a forum id
     *
     * @return Forum - the forum.
     * @exception CategoryNotFoundException
     */
    public Forum getForum( final int forumID ) {
        if( (forumID - 1) > forums.length ){
            return null;
        }else{
            return forums[ forumID - 1 ];
        }
    }

    /**
     * Retrun a list of forums
     *
     * @return Forum[] - A array of forums
     */
    public Forum[] getForumCategory () {
        return forums;
    }
}//EOC