Detailed explanation of using XPath in dom4j (with code)

This time I will bring you a detailed explanation of using XPath in dom4j (with code). What are the precautions for using XPath in dom4j. Here are practical cases, let’s take a look.

looks like this:

package com.wzh.test.xpath;
 
import java.io.File;
 
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;
 
public class Demo4 {
 
  public static void main(String[] args) throws DocumentException {
    SAXReader reader=new SAXReader();
    Document document=reader.read(new File("src/book.xml"));
     
    String value=document.selectSingleNode("//书名").getText();
    System.out.println(value);
     
     
    //检测xml文档是否有匹配的用户名和密码
    String username="aaa";
    String password="123";
    reader=new SAXReader();
    document=reader.read(new File("src/users.xml"));
    Node node=document.selectSingleNode("//user[@username='"+username+"'" +
        " and @password='"+password+"']");
    if(node==null)
    {
      System.out.println("用户名密码错误");
    }
    else
    {
      System.out.println("登录成功");
    }
  }
}

book.xml

<?xml version="1.0" encoding="utf-8"?>
<书架>
   <书>
   <书名>Java就业培训教材</书名>
     <作者>张孝祥</作者>
     <售价>39.00元</售价>
   </书>
   <书>
   <书名>Java网页开发</书名>
     <作者>张孝祥</作者>
     <售价>29.00元</售价>
   </书>
</书架>

users. xml

<?xml version="1.0" encoding="UTF-8"?>
<users>
  <user id="1" username="aaa" password="123" email="aa@sina.com"></user>
  <user id="2" username="bbb" password="456" email="bb@sina.com"></user>
</users>

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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