Java 内置的读取XML方法

URL url = new URL(urlString);
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser parser = factory.newSAXParser();
XMLReader xmlReader = parser.getXMLReader();
//RssHandler:XML 节点读取方式实现
RssHandler rssHandler = new RssHandler(); 
xmlReader.setContentHandler(rssHandler);
InputSource inputSource = new InputSource(url.openStream());
xmlReader.parse(inputSource);
return rssHandler.getRssFeed();

 RssHandler 帮助类

public class RssHandler extends DefaultHandler {
    //多个Item集合
    RSSFeed rssFeed ;
    //单个Item实例
    RssItem rssItem; 
    CurrentState currentState = CurrentState.None;
    
    public RssHandler(){}
    
    public RSSFeed getRssFeed(){
        return this.rssFeed;
    }
    
    public void startDocument()throws SAXException {
        this.rssFeed = new RSSFeed();
        this.rssItem = new RssItem();
    }
    
    public void startElement(String _URI,String localName,String qNameString,Attributes atts)throws SAXException 
    {
        if(localName.equals("channel")){
            currentState = CurrentState.None; 
        }
        else if(localName.equals("item")){
            this.rssItem = new RssItem(); 
        }
        else if(localName.equals("title")){
            currentState = CurrentState.TITLE; 
        }
        else if(localName.equals("description")){
            currentState = CurrentState.DESCRIPTION; 
        }
        else if(localName.equals("link")){
            currentState = CurrentState.LINK; 
        }
        else if(localName.equals("category")){
            currentState = CurrentState.CATEGORY; 
        }
        else if(localName.equals("pubDate")){
            currentState = CurrentState.PUBDATE; 
        } 
    }
    
    public void endElement(String _URI,String localName,String qName)throws SAXException
    {
        if(localName.equals("item")){
            this.rssFeed.addItem(this.rssItem);
        }
    }
    
    public void characters(char ch[],int start,int length)
    {
        String theString = new String(ch,start,length);
        switch (currentState) {
        case TITLE:
            this.rssItem.title(theString);
            currentState = CurrentState.None;
            break;
        case LINK:
            this.rssItem.link(theString);
            currentState = CurrentState.None;
            break;
        case DESCRIPTION:
            this.rssItem.description(theString);
            currentState = CurrentState.None;
            break;
        case CATEGORY:
            this.rssItem.category(theString);
            currentState = CurrentState.None;
            break;
        case PUBDATE:
            this.rssItem.publicDate(theString);
            currentState = CurrentState.None;
            break; 
        default:
            break;
        }
    } 
    /*
     * 节点枚举
     */
     public enum CurrentState{
        /*
         * 无
         */
        None,
        TITLE,
        LINK,
        DESCRIPTION,
        CATEGORY,
        PUBDATE 
    }
}