JAVA操作XML文件 - SAX操作

事件驱动方式的解析

package com.gyarmy.sax;

import java.io.IOException;

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

import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;
/*
 * 结论:
 * 碰到实现接口中的方法,但是只有很少的方法和我们有关时,去找默认的实现类
 * 
 * 
 */
public class SaxTest1 {

	public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
		// TODO Auto-generated method stub
		//拿到工厂
				SAXParserFactory factory = SAXParserFactory.newInstance();
				
				//拿到解析器对象
				SAXParser parser =  factory.newSAXParser();
				XMLReader reader = parser.getXMLReader();
				reader.setContentHandler(new MyContentHandler());
				//去解析 XML文件
				reader.parse("src/demo1.xml"); 
	}
}

class MyContentHandler extends DefaultHandler{
	//重写目标方法
		//alt + shift + S 
		//选择重写的方法
	//定义boolean值 和 计数器,是非常常规的小技巧
	protected int i=0;
	
	@Override
	public void startDocument() throws SAXException {
		// TODO Auto-generated method stub
		//System.out.println("文档开始");
	}

	@Override
	public void endDocument() throws SAXException {
		// TODO Auto-generated method stub
		//System.out.println("文档结束");
	}

	@Override
	public void startElement(String uri, String localName, String qName,
			Attributes attributes) throws SAXException {
		// TODO Auto-generated method stub
		//System.out.println("元素开始:"+qName);
		
		if(qName == "售价")
		{
			//endElement();
			i = 1;
			//System.out.println(attributes.get);
			//return;
		}
		/*
		for(int i=0;i<attributes.getLength();i++)
		{
			String name = attributes.getQName(i);
			String value = attributes.getValue(i);
			System.out.println(i + "--" + name+":"+value);
		}
		*/
		
		
	}

	@Override
	public void endElement(String uri, String localName, String qName)
			throws SAXException {
		// TODO Auto-generated method stub
		if(qName == "售价")
		{
			
			i = 0;
		}
		//System.out.println("元素结束:"+qName);
	}

	@Override
	public void characters(char[] ch, int start, int length)
			throws SAXException {
		// TODO Auto-generated method stub
		if(i == 1)
		{
			System.out.println(new String(ch,start,length));
		}
	}
	
	
}