利用Xpath实现一个简单的登录验证程序

package cn.daomain;

import java.io.File;

import java.util.List;

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.Node;

import org.dom4j.io.SAXReader;

public class XpathDemo {

public static void main(String[] args) throws DocumentException {

method_1();

}

//获取某一个属性

public static void method_1() throws DocumentException{

//得到解析器

SAXReader reader = new SAXReader();

Document document = reader.read(new File("src/cn/xml/MyXml.xml"));

//拿到所有的

// List<Node> nodes = document.selectNodes("//书名");

// for(Node node : nodes){

// System.out.println(node.getText());

// }

//拿到某一个

String value = document.selectSingleNode("/bookrack/book[1]/书名").getText();

System.out.println(value);

}

//实现简单的登录验证

public static void method_2() throws DocumentException{

String username = "aaa";

String password = "123";

//得到一个解析器

SAXReader reader = new SAXReader();

Document document = reader.read(new File("src/cn/xml/UserXml.xml"));

//这里找的是user下面的属性

Node node = document.selectSingleNode("//user[@username = '"+username+"' and @password = '"+password+"']");

System.out.println(node);

if(node != null){

System.out.println("登录成功");

}else{

System.out.println("账号或密码错误");

}

}

}