阿九说：Dom4j解析XML

　　1.先创建一个info.xml

 1 <phoneInfo>
 2     <brand name="小米">
 3         <type name="小米8"/>
 4         <type name="小米9"/>
 5         <type name="小米MIX"/>
 6     </brand>
 7     <brand name="iphone">
 8         <type name="iphone7"/>
 9         <type name="iphone8"/>
10         <type name="iphoneX"/>
11     </brand>
12     <brand name="华为">
13         <type name="华为P30"/>
14         <type name="华为P20"/>
15         <type name="华为P30 pro"/>
16     </brand>
17 </phoneInfo>

info.xml

　　2.创建解析XML类Test(解析XML节点及属性的操作)

package cn.kgc.dom4jtest;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import java.util.Iterator;

/**
 * xml解析
 */
public class Test {
    private SAXReader reader;

    public static void main(String[] args) throws Exception {
        SAXReader reader = new SAXReader();
        //读取xml文件，并生成document对象，现可通过document来操作文档
        Document document = reader.read("src/info.xml");
        //获取文档的根节点
        Element rootElement = document.getRootElement();
        System.out.println("根节点的名字是"+rootElement.getName());
        //获取子节点列表
        Iterator iterator = rootElement.elementIterator();
        while (iterator.hasNext()){
            //获取节点的名字
            Element firstChild = (Element) iterator.next();
            //System.out.println(firstChild.getName());
            //获取节点的属性值
            System.out.println(firstChild.attribute("name").getValue());
            //获取子节点的下一级节点
            Iterator iterator1 = firstChild.elementIterator();
            while (iterator1.hasNext()){
                Element element = (Element) iterator1.next();
                System.out.println("	"+element.attributeValue("name"));
            }
        }
    }
}

Test.java

　　3.创建添加节点的类AddTest(添加节点及属性的操作)

 1 package cn.kgc.dom4jtest;
 2 
 3 import org.dom4j.Document;
 4 import org.dom4j.Element;
 5 import org.dom4j.io.SAXReader;
 6 import org.dom4j.io.XMLWriter;
 7 
 8 import java.io.File;
 9 import java.io.FileOutputStream;
10 import java.io.OutputStream;
11 
12 /**
13  * 添加节点的操作
14  */
15 public class AddTest1 {
16     public static void main(String[] args) throws Exception {
17         SAXReader reader=new SAXReader();
18         Document document=reader.read("src/info.xml");
19         //获取到根节点
20         Element rootElement = document.getRootElement();
21         //添加一个子节点
22         Element newEle = rootElement.addElement("brand");
23         //给当前节点添加属性
24         newEle.addAttribute("name","魅族");
25         Element type1 = newEle.addElement("type");
26         type1.addAttribute("name","s16");
27         OutputStream o=new FileOutputStream(new File("src/info.xml"));
28         XMLWriter xmlWriter=new XMLWriter(o);
29         xmlWriter.write(rootElement);
30         xmlWriter.flush();
31         xmlWriter.close();
32     }
33 }

AddTest.java

　　4.创建修改节点及属性的类UpdateTest(修改节点及属性的操作)

 1 package cn.kgc.dom4jtest;
 2 
 3 import org.dom4j.Document;
 4 import org.dom4j.Element;
 5 import org.dom4j.io.SAXReader;
 6 import org.dom4j.io.XMLWriter;
 7 
 8 import java.io.File;
 9 import java.io.FileOutputStream;
10 import java.util.Iterator;
11 
12 /**
13  * 执行修改操作
14  */
15 public class UpdateTest {
16     public static void main(String[] args) throws Exception {
17         SAXReader reader=new SAXReader();
18         Document document=reader.read("src/info.xml");
19         //获取根节点
20         Element rootElement = document.getRootElement();
21         Iterator iterator = rootElement.elementIterator();
22         while (iterator.hasNext()){
23             Element firstEle = (Element) iterator.next();
24             System.out.println(firstEle.attributeValue("name"));
25             if (firstEle.attributeValue("name").equals("魅族")){
26                 Iterator type = firstEle.elementIterator();
27                 while (type.hasNext()){
28                     Element next = (Element) type.next();
29                     if (next.attributeValue("name").equals("s16")){
30                         next.addAttribute("name","16 pro");
31                     }
32                 }
33             }
34         }
35         XMLWriter xmlWriter=new XMLWriter(new FileOutputStream(new File("src/info.xml")));
36         xmlWriter.write(rootElement);
37         xmlWriter.flush();
38         xmlWriter.close();
39     }
40 }

UpdateTest.java

　　5.创建删除节点及属性的类DelTest(删除节点及属性的操作)

 1 package cn.kgc.dom4jtest;
 2 
 3 import org.dom4j.Document;
 4 import org.dom4j.Element;
 5 import org.dom4j.io.SAXReader;
 6 import org.dom4j.io.XMLWriter;
 7 
 8 import java.io.File;
 9 import java.io.FileOutputStream;
10 import java.util.Iterator;
11 
12 /**
13  * 执行操作
14  */
15 public class DelTest {
16     public static void main(String[] args) throws Exception {
17         SAXReader saxReader=new SAXReader();
18         Document document = saxReader.read("src/info.xml");
19         Element rootElement = document.getRootElement();
20         Iterator iterator = rootElement.elementIterator();
21         while (iterator.hasNext()){
22              Element element = (Element) iterator.next();
23              if (element.attributeValue("name").equals("魅族")){
24                 //通过父节点删除子节点
25                 element.getParent().remove(element);
26              }
27         }
28         XMLWriter writer=new XMLWriter(new FileOutputStream(new File("src/info.xml")));
29         writer.write(rootElement);
30         writer.flush();
31         writer.close();
32     }
33 }

DelTest