Xml—dom4j解析—简单的用户登录管理系统

users.xml

<?xml version="1.0" encoding="UTF-8"?>
<users>
 <user username="aaa" password="111"/>
 <user username="bbb" password="222"/>
 <user username="ccc" password="333"/>
</users>

 

Xpath.java

package yyy.dom4j;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;

 

public class Xpath {

 private static boolean b;
 private static int count = 1;
 public static void main(String[] args) throws Exception {
  login();
 }

 private static void login() throws IOException, DocumentException {
  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  System.out.print("请输入用户名:");
  String username = br.readLine();
  System.out.print("请输入密码:");
  String password = br.readLine();
  
  SAXReader reader = new SAXReader();
  Document document = reader.read(new File("src/users.xml"));
  //利用Xpath技术获得匹配用户名username和密码password的节点
  Node node = document.selectSingleNode("//user[@username='"+username+"' and @password='"+password+"']");
  if(node==null)
   b = false;
  else
   b = true;
  if(b){
   System.out.println("登陆成功！！");
   return;
  }
  else{
   System.out.println("账号或密码错误，请重新输入！！！");
   login();
  }
 }

}