<?xml version="1.0" encoding="UTF-8"?>

<student> 
  <stu> 
    <name>張三</name>  
    <age>16</age>  
    <sex>男</sex> 
  </stu>  
  <stu> 
    <name>李四</name>  
    <age>18</age>  
    <sex>男</sex> 
  </
 
stu>  
  <stu> 
    <name>王五</name>  
    <age>17</age>  
    <sex>男</sex> 
  </stu> 
</student>

package cn.itcast.vo;

public class Student {
    private String name;
    private int age;
    private String sex;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public String toString(){
        return name+":"+age+":"+sex;
    }
}
 

package student;

import java.io.FileOutputStream;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

import cn.itcast.vo.Student;

public class StuServer {
    //增加
    public static void addStu(Student s) throws Exception{
        SAXReader sax = new SAXReader();
        Document document = sax.read("src/student.xml");
        Element root = document.getRootElement();
        Element stu = root.addElement("stu");
        Element name = stu.addElement("name");
        Element age = stu.addElement("age");
        Element sex = stu.addElement("sex");
        name.setText(s.getName());
        age.setText(s.getAge()+"");
        sex.setText(s.getSex());
        //回寫
        OutputFormat format = OutputFormat.createPrettyPrint();
        XMLWriter  xmlwriter = new XMLWriter(new FileOutputStream("src/student.xml"),format);
        xmlwriter.write(document);
        xmlwriter.close();
    }
    //刪除  根據學生的id
    public  static void delStu(String name)throws Exception{
        SAXReader sax = new SAXReader();
        Document document = sax.read("src/student.xml");
        List
 
<Node> list=document.selectNodes("//name");
        for(Node node:list){
            String namev = node.getText();
            if(namev.equals(name)){
                Element stu = node.getParent();
                Element student = stu.getParent();
                student.remove(stu);
            }
        }
        //回寫
        OutputFormat format = OutputFormat.createPrettyPrint();
        XMLWriter  xmlwriter = new XMLWriter(new FileOutputStream("src/student.xml"),format);
        xmlwriter.write(document);
        xmlwriter.close();
    }
    public static Student selectStu(String name)throws Exception{
        SAXReader sax = new SAXReader();
        Document document = sax.read("src/student.xml");
        List<Node>list = document.selectNodes("//name");
        Student s = new Student();
        for(Node node : list){
            String namev = node.getText();
            if(namev.equals(name)){
                Element stu = node.getParent();
                int agev =Integer.parseInt(stu.element("age").getText());
                String sexv = stu.element("sex").getText();
                s.setAge(agev);
                s.setName(namev);
                s.setSex(sexv);
            }
        }
        return s;
    }
}

package cn.itcast.test;

import cn.itcast.vo.Student;
import student.StuServer;

public class Test {

    public static void main(String[] args) throws Exception{
//        addTest();
//        delTest();
        selectTest();

    }
    public static void  addTest() throws Exception{
        Student s = new Student();
        s.setName("tom");
        s.setAge(20);
        s.setSex("男");
        StuServer.addStu(s);
    }
    public  static void delTest()throws Exception{
        StuServer.delStu("tom");
    }
    public static void selectTest()throws Exception{
        Student student = StuServer.selectStu("王五");
        System.out.println(student.toString());
    }

}

xml+dom4j+xpath學生管理系統