DOM4J解析XML

1.导入dom4j的包
2.DOM4JParse.java

package com.lijun.xml.dom4j;

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.util.Iterator;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.DOMReader;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class DOM4JParse {

	public static void main(String[] args) throws Exception {
		
		createXML();
		
		parseXMLofSAXReader();
		
		parseXMLOfDOMReader();
	}
	
	/**
	 * 生成XML文件
	 * @throws Exception
	 */
	private static void createXML() throws Exception {
		//创建XML根的第一种方式
//		Document doc=DocumentHelper.createDocument();
//		Element root=DocumentHelper.createElement("root");
//		doc.setRootElement(root);
		
		Element root=DocumentHelper.createElement("studnet");
		Document doc=DocumentHelper.createDocument(root);
		
		root.addAttribute("name","zs");
		
		Element e1=root.addElement("e1");
		Element e2=root.addElement("e2");
		
		e1.setText("hello");
		e2.setText("world");
		
		e1.addAttribute("age","20");
		
		//输出控制台，默认格式
		XMLWriter out=new XMLWriter();
		out.write(doc);
		
		//输出到文件，默认格式
		XMLWriter out2=new XMLWriter(new FileOutputStream("studnet1.xml"));
		out2.write(doc);
		
		//输出到文件，指定格式
		OutputFormat format=new OutputFormat("    ",true);
		XMLWriter out3=new XMLWriter(new FileOutputStream("student2.xml"),format);
		out3.write(doc);
		
		//用FileWrite输出到文件，指定格式，需刷新
		XMLWriter out4=new XMLWriter(new FileWriter("student3.xml"),format);
		out4.write(doc);
		out4.flush();
	}
	
	/**
	 * 解析XML用SAX
	 * @throws Exception 
	 */
	private static void parseXMLofSAXReader() throws Exception{
		SAXReader reader=new SAXReader();
		Document doc=reader.read(new File("student1.xml"));
		
		Element root=doc.getRootElement();
										   
		System.out.println(root.getName());
		
		List list=root.elements();
		
		System.out.println(list.size());
		
		List list2=root.elements("e1");
		
		System.out.println(list2.size());
		
		Element firste1=root.element("e1");
		
		System.out.println(firste1.attributeValue("age"));
		
		for(Iterator it=root.elementIterator();it.hasNext();){
			Element element=(Element)it.next();
			System.out.println(element.attributeValue("age"));
		}
	}

	/**
	 * 解析XML用DOM
	 * @throws Exception 
	 * 
	 */
	private static void parseXMLOfDOMReader() throws Exception{
		//获得W3C的DOCUMENT
		DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
		DocumentBuilder builder=factory.newDocumentBuilder();
		org.w3c.dom.Document docw3c=builder.parse(new File("student2.xml"));
		
		//将JAXP的document文档转换成dom4j的document
		DOMReader reader1=new DOMReader();
		Document doc1=reader1.read(docw3c);
		
		Element root=doc1.getRootElement();
		
		System.out.println(root.getName());
	}
}