【重点：Xpath讲解】Xpath：xml的小型查询语言，具有强大的功能

<?xml version="1.0" encoding="UTF-8"?>
<xml-body>
<user username="jingtian" password="124343"></user>
<user username="xiaozhi" password="124343"></user>
</xml-body>

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

public class XpathTest
{
public static void main(String[] args) throws Exception
{
String username = "jingtian";
String password = "124343";

SAXReader reader = new SAXReader();
Document document = reader.read("users.xml");

Node node=document.selectSingleNode("//user[@username='" + username+ "' and @password='" + password + "']");
if(node==null)
System.out.println("用户名或者密码错误！");
else
System.out.println("登陆成功！");
}
}