jaxp的Sax解析

<?xml version="1.0" encoding="UTF-8"?>
<CATALOG>
    <CD>
        <TITLE>Empire Burlesque</TITLE>
        <ARTIST>Bob Dylan</ARTIST>
        <COUNTRY>USA</COUNTRY>
        <COMPANY>Columbia</COMPANY>
        <PRICE>10.90</PRICE>
        <YEAR>1985</YEAR>
    </CD>
    <CD>
        <TITLE>Hide your heart</TITLE>
        <ARTIST>Bonnie Tyler</ARTIST>
        <COUNTRY>UK</COUNTRY>
        <COMPANY>CBS Records</COMPANY>
        <PRICE>9.90</PRICE>
        <YEAR>1988</YEAR>
    </CD>
    <CD>
        <TITLE>Greatest Hits</TITLE>
        <ARTIST>Dolly Parton</ARTIST>
        <COUNTRY>USA</COUNTRY>
        <COMPANY>RCA</COMPANY>
        <PRICE>9.90</PRICE>
        <YEAR>1982</YEAR>
    </CD>
    <CD>
        <TITLE>Still got the blues</TITLE>
        <ARTIST>Gary Moore</ARTIST>
        <COUNTRY>UK</COUNTRY>
        <COMPANY>Virgin records</COMPANY>
        <PRICE>10.20</PRICE>
        <YEAR>1990</YEAR>
    </CD>
    <CD>
        <TITLE>Eros</TITLE>
        <ARTIST>Eros Ramazzotti</ARTIST>
        <COUNTRY>EU</COUNTRY>
        <COMPANY>BMG</COMPANY>
        <PRICE>9.90</PRICE>
        <YEAR>1997</YEAR>
    </CD>
    <CD>
        <TITLE>One night only</TITLE>
        <ARTIST>Bee Gees</ARTIST>
        <COUNTRY>UK</COUNTRY>
        <COMPANY>Polydor</COMPANY>
        <PRICE>10.90</PRICE>
        <YEAR>1998</YEAR>
    </CD>
</CATALOG>

import java.io.IOException;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class SaxParse {

    public static void main(String[] args) {
            SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
            try {
                SAXParser saxParser = saxParserFactory.newSAXParser();
                MyHandler myHandler=new MyHandler();
                saxParser.parse("cd.xml", myHandler);
                
            } catch (ParserConfigurationException e) {
                e.printStackTrace();
            } catch (SAXException e) {
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        
    }
}

class MyHandler extends DefaultHandler{//继承DefaultHandler,然后重写父类方法
    //两个类成员,用于在方法之间保存数据
    boolean flag=false;
    String artist;
    @Override
    public void startDocument() throws SAXException {
        //System.out.println("MyHandler.startDocument()====>开始解析文档");
    }

    @Override
    public void endDocument() throws SAXException {
        //System.out.println("MyHandler.endDocument()====>结束解析文档");
    }

    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
        //System.out.println("MyHandler.startElement()====>开始解析元素");
        //解析到了<ARTIST>这一元素,传递一个信号给characters()方法,将每个作者都保存到artist
        if (qName.equals("ARTIST")) {
            flag=true;
        }

    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        //System.out.println("MyHandler.endElement()====>结束解析元素");
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        //System.out.println("MyHandler.characters()====>得到元素的文本");
        //解析到了<ARTIST>这一元素,将每个作者都保存到artist
        if (flag) {
            artist=new String(ch, start, length);
            flag=false;
        }
        //如果<COUNTRY>元素的文本是UK,就输出作者名字
        String uk=new String(ch, start, length);
        if (uk.equals("UK")) {
            System.out.println("The artist from UK----->"+artist);
        }    
    }
        
    
    
}