一、Java中操作DOM中常用的类

• Node 
  数据类型基类
• Element 
  最常用的类
• Attr 
  Element的属性
• Text 
  Element or Attr的内容
• Document 
  代表整个XML文档，代表DOM tree

二、xml文件

<?xml version = "1.0" encoding = "utf-8"?>
<books>
    <book id="1">
        <name>冰与火之歌</name>
        <author>张三</author>
        <pice>99</pice>
    </book>
    <book id="2">
        <name>葫芦娃</name>
        <pice>99</pice>
        <year>1993</year>
    </book>
</books>

三、Dom解析XML案例Demo

package com.da.dom;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class DomTest {

    public static void main(String[] args) {
        //创建一个DocumentBuilderFactory对象
        DocumentBuilderFactory documentBuilder = DocumentBuilderFactory.newInstance();
        try {
            //创建DocumentBuilder对象
            DocumentBuilder db = documentBuilder.newDocumentBuilder();
            //通过DocumentBuilder中的parse方法加载book。xml文件到当前项目下
            Document document = db.parse("books.xml");
            //获取所有book节点的集合
            NodeList nodeList = document.getElementsByTagName("book");
            //遍历每个book节点
            for (int i = 0; i < nodeList.getLength(); i++) {
                System.out.println("==========第"+(i+1)+"本==========");
//                Node book = nodeList.item(i);
//                NamedNodeMap attributes = book.getAttributes();
//                //不知道当前节点下有多少参数属性值
//                for (int j = 0; j < attributes.getLength(); j++) {
//                    Node item = attributes.item(j);
//                    System.out.print("获取属性名:"+item.getNodeName());
//                    System.out.println("获取属性值:"+item.getNodeValue());
//                }
                //确切当前参数下有多少参数属性值
                Element element = (Element) nodeList.item(i);
                System.out.println("id值："+element.getAttribute("id"));
                //获取book下面的子节点
                NodeList childNodes = nodeList.item(i).getChildNodes();
                for (int j = 0; j < childNodes.getLength(); j++) {
                    if (childNodes.item(j).getNodeType() == Node.ELEMENT_NODE) {
                        System.out.print(childNodes.item(j).getNodeName()+":");
                        System.out.println(childNodes.item(j).getTextContent());
                    };
                }
                
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}