xml解析

import java.io.File;

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

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;


public class XmlTest {
	public void getAllUserName(String fileName){
		try {
			/*
			 * 1、獲得DOM解析器工廠類
			 * 2、得到DOM解析器
			 * 3、得到xml文件File
			 * 4、解析xml文件獲得Document對象
			 * 5、得到xml文件的根節點
			 * 6、得到根節點下的所有子節點
			 */
			DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
			DocumentBuilder db = dbf.newDocumentBuilder();
			
			File file = new File(fileName);
			if(file.exists()){
				Document doc = db.parse(file);
				Element e = doc.getDocumentElement();
				
				System.out.println("root document:"+e.getNodeName());
				
				NodeList nodeList = e.getElementsByTagName("student");
				if(nodeList!=null&&nodeList.getLength()>0){
					for(int i=0;i<nodeList.getLength();i++){
						//7、循環節點
						Node node = nodeList.item(i);
						if(node.getNodeType()==Node.ELEMENT_NODE){
							System.out.println("======開始解析=====");
							Element nameE = (Element)node;
							NodeList nameNodeList= nameE.getElementsByTagName("name");
							System.out.println("name:"+nameNodeList.item(0).getChildNodes().item(0).getNodeValue());
							
							Element gradeE = (Element)node;
							NodeList gradeNodeList= gradeE.getElementsByTagName("grade");
							System.out.println("grade:"+gradeNodeList.item(0).getChildNodes().item(0).getNodeValue());
							
							Element ageE = (Element)node;
							NodeList ageNodeList= ageE.getElementsByTagName("age");
							System.out.println("age:"+ageNodeList.item(0).getChildNodes().item(0).getNodeValue());
						}
					}
					
				}else{
					System.exit(1);
				}
			}
		} catch(Exception e){
			
		}
		
	}
	public static void main(String[] args) {
		XmlTest xt = new XmlTest();
		xt.getAllUserName("e:\\test.xml");
	}
}

xml文件內容

<?xml version="1.0"?> 
<students> 
    <student> 
        <name>111</name> 
        <grade>B</grade> 
        <age>23</age> 
    </student> 
    <student> 
        <name>222</name> 
        <grade>A</grade> 
        <age>24</age> 
    </student> 
    <student> 
        <name>333</name> 
        <grade>A</grade> 
        <age>25</age> 
    </student> 
</students>