java 解析XML

       目前配置文件在项目开发中非常常见，想properties，xml，json, ini 等等，今天我们来简单介绍一下怎么解析XML。 解析XML有很多种方法，其中可以分为两大类，一个是DOM，另一个是SAX。

<?xml version=”1.0″?> <employees>      <employee>        <name>leon</name>        <sex>m</sex>        <age>24</age>     </employee>     </employees>   

下面是Java Code

package com.trend;import java.io.File;import java.io.IOException;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.parsers.ParserConfigurationException;import javax.xml.transform.Transformer;import javax.xml.transform.TransformerConfigurationException;import javax.xml.transform.TransformerException;import javax.xml.transform.TransformerFactory;import javax.xml.transform.dom.DOMSource;import javax.xml.transform.stream.StreamResult;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.NodeList;import org.xml.sax.SAXException;public class Xmlfile {                                              //解析XMLpublic void paraseXml(File filename){DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();      //得到Document解析工厂实例try {DocumentBuilder builder=factory.newDocumentBuilder();            //创建DOM解析器    Document doc=builder.parse(filename);NodeList n=doc.getElementsByTagName("employee");for(int i=0;i<n.getLength();i++){System.out.println("Names is "+doc.getElementsByTagName("name").item(i).getFirstChild().getNodeValue());System.out.println("Age is "+doc.getElementsByTagName("age").item(i).getFirstChild().getNodeValue());System.out.println("Sex is "+doc.getElementsByTagName("sex").item(i).getFirstChild().getNodeValue());}} catch (ParserConfigurationException e) {e.printStackTrace();} catch (SAXException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}public void appendNode(File filename){                       //添加节点DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();try {DocumentBuilder builder=factory.newDocumentBuilder(); try {Document doc=builder.parse(filename);//this.document = builder.newDocument(); Element root= (Element)doc.getElementsByTagName("employees").item(0);  //获取根节点//System.out.println(root.get);Element employee=doc.createElement("employee");//创建employee节点Element name = doc.createElement("name");          //创建namename.appendChild(doc.createTextNode("Li"));employee.appendChild(name);Element age=doc.createElement("age");           //创建ageage.appendChild(doc.createTextNode("25"));employee.appendChild(age);Element sex =doc.createElement("sex");          //创建sexsex.appendChild(doc.createTextNode("w"));employee.appendChild(sex);root.appendChild(employee);                    //添加employeeTransformerFactory tFactory =TransformerFactory.newInstance(); Transformer transformer; try {transformer = tFactory.newTransformer();DOMSource source = new DOMSource(doc); StreamResult result = new StreamResult(filename); try {transformer.transform(source, result);} catch (TransformerException e) {// TODO Auto-generated catch blocke.printStackTrace();} } catch (TransformerConfigurationException e) {// TODO Auto-generated catch blocke.printStackTrace();}                        } catch (SAXException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}} catch (ParserConfigurationException e) {// TODO Auto-generated catch blocke.printStackTrace();}}          }

下面是测试类：

package com.trend;import java.io.File;public class paraseXml {public static void main(String[] args) {File file =new File("E:\\123.xml");Xmlfile xml = new Xmlfile();xml.paraseXml(file);           //解析xml.appendNode(file);               //添加xml.paraseXml(file);                //添加后再次解析}}