[移动开发]XML笔记

xml解析技术介绍

dom4j

/*
链接：https://pan.baidu.com/s/1OOTRbZWjQyOvZasqgMIbzw 
提取码：wc2d
*/

1. 导入相关依赖
   

2. 将要读取的xml文件

<?xml version="1.0" encoding="UTF-8" ?>
<books>
    <book sn="SN123123123">
        <name>辟邪剑谱</name>
        <price>99</price>
        <author>班主任</author>
    </book>
    <book sn="SN123123123">
        <name>葵花宝典</name>
        <price>99.9</price>
        <author>班长</author>
    </book>
</books>

3. 生成对应对象的set，get，以及toString方法

package com.atguigu.pojo;

import java.math.BigDecimal;

public class Book {
    private String sn;
    private String name;

    public Book(String sn, String name, BigDecimal price, String author) {
        this.sn = sn;
        this.name = name;
        this.price = price;
        this.author = author;
    }

    private BigDecimal price;

    public Book() {
    }

    private String author;

    public void setSn(String sn) {
        this.sn = sn;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getSn() {
        return sn;
    }

    public String getName() {
        return name;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public String getAuthor() {
        return author;
    }

    @Override
    public String toString() {
        return "Book{" +
                "sn='" + sn + '\'' +
                ", name='" + name + '\'' +
                ", price=" + price +
                ", author='" + author + '\'' +
                '}';
    }
}

4. 读取

package com.atguigu.pojo;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.junit.Test;

import java.math.BigDecimal;
import java.util.List;

public class Dom4jTest {
    @Test
    public void test1(){
        //创建一个SaxReader输入流，去读取xml配置文件，生成Document对象
        SAXReader saxReader = new SAXReader();
        try {
            Document document = saxReader.read("src/books.xml");
            System.out.println(document);
        }catch (Exception e){
            e.printStackTrace();
        }
    }


    //读取books.xml文件生成Book类
    @Test
    public void test2() throws Exception{
        //1.读取xml文件
        SAXReader reader = new SAXReader();
        //2.通过Document对象获取元素
        Document document = reader.read("src/books.xml");
        Element rootElement = document.getRootElement();
        //3.通过根元素获取book标签对象
        List<Element> books = rootElement.elements("book");
        //遍历，处理每个book标签转换为Book类
        for(Element book :books){
            //asXML()把标签对象转化为标签字符串
            Element nameElement = book.element("name");
            //getText();方法可以获取标签中的文本内容
            String nameText = nameElement.getText();
            //直接获取指定标签的文本内容
            String priceText =  book.elementText("price");
            String authorText = book.elementText("author");

            String snValue = book.attributeValue("sn");

            System.out.println(new Book(snValue, nameText, new BigDecimal(priceText), authorText));
        }

    }
}