使用jaxp完成SAX編程

Book.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?><書架>
	<書 name="yyy">
		<售價>666</售價>
		<售價>39</售價><書名>java就業培訓</書名>
		<作者>粑粑</作者>
	<售價>233</售價></書>
</書架>

package sax;

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.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

public class Demo1 {

	/**
	 * SAX方式解析book.xml
	 * @throws SAXException 
	 * @throws ParserConfigurationException 
	 * @throws IOException 
	 */
	public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
		//1. 創建工廠
		SAXParserFactory factory = SAXParserFactory.newInstance();
		
		//2. 用工廠創建解析器
		SAXParser sp = factory.newSAXParser();
		
		//3. 利用解析器得到reader
		XMLReader reader = sp.getXMLReader();	
		
		//4. 在解析xml文檔之前，設置好時間處理器
		reader.setContentHandler(new MyContentHandler2());
		
		//5. 利用reader讀取xml文檔
		reader.parse("src/book.xml");
		
	}
}

//得到xml文檔內容的事件處理器
class MyContentHandler implements ContentHandler{

	@Override
	public void setDocumentLocator(Locator locator) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void startDocument() throws SAXException {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void endDocument() throws SAXException {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void startPrefixMapping(String prefix, String uri) throws SAXException {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void endPrefixMapping(String prefix) throws SAXException {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
		// TODO Auto-generated method stub
		System.out.println("當前解析到了："+qName+"，這個標籤是開始標籤");
		for(int i = 0; i < atts.getLength(); i ++) {
			String attName = atts.getQName(i);
			String attValue = atts.getValue(i);
			
			System.out.println(attName+"  "+attValue);
		}
	}

	@Override
	public void endElement(String uri, String localName, String qName) throws SAXException {
		// TODO Auto-generated method stub
		System.out.println("當前解析到了："+qName+"，這個標籤是結束標籤");
	}

	@Override
	public void characters(char[] ch, int start, int length) throws SAXException {
		// TODO Auto-generated method stub
		System.out.println("當前解析到了內容："+new String(ch,start,length));
	}

	@Override
	public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void processingInstruction(String target, String data) throws SAXException {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void skippedEntity(String name) throws SAXException {
		// TODO Auto-generated method stub
		
	}
}

//用於獲取第一個售價節點的值：<售價》666</售價>
class MyContentHandler2 extends DefaultHandler{
	private boolean isOk = false;
	private int index = 1;

	@Override
	public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
		if(qName.equals("售價")&&index==1) {
			isOk = true;
		}
	}

	@Override
	public void endElement(String uri, String localName, String qName) throws SAXException {
		if(qName.equals("售價")) {
			isOk = false;
			index++;
		}
	}

	@Override
	public void characters(char[] ch, int start, int length) throws SAXException {
		if(isOk==true) {
			System.out.println(new String(ch, start, length));
		}
	}
	
}