<?xml version="1.0" encoding="utf-8" ?>
<books>
    <book id="SN123123413241">
        <name>java编程思想</name>
        <author>华仔</author>
        <price>9.9</price>
    </book>
    <book id="SN12341235123">
        <name>葵花宝典</name>
        <author>班长</author>
        <price>5.5</price>
    </book>
</books>

 实体类

package com;

import java.math.BigDecimal;
import java.util.Objects;

/**
 * @author hrui
 * @date 2023/10/20 16:39
 */
public class Book {

    private String sn;
    private String name;
    private BigDecimal price;
    private String author;

    public Book() {
    }

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

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

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Book book = (Book) o;
        return Objects.equals(sn, book.sn) && Objects.equals(name, book.name) && Objects.equals(price, book.price) && Objects.equals(author, book.author);
    }

    @Override
    public int hashCode() {
        return Objects.hash(sn, name, price, author);
    }

    public String getSn() {
        return sn;
    }

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

    public String getName() {
        return name;
    }

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

    public BigDecimal getPrice() {
        return price;
    }

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

    public String getAuthor() {
        return author;
    }

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

package com;

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

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

/**
 * @author hrui
 * @date 2023/10/20 16:42
 */
public class Dom4jTest {

    @Test
    public void test01(){
        //创建一个SaxReader输入流,去读取xl配置文件,生成Document对象
        SAXReader saxReader=new SAXReader();
        Document document= null;
        try {
            document = saxReader.read("src/books.xml");
        } catch ( Exception e) {
            e.printStackTrace();
        }
        System.out.println(document);
    }

    //读取books.xml文件生成Book类
    @Test
    public void test02() throws DocumentException {
        String projectRoot = System.getProperty("user.dir");
        System.out.println(projectRoot);
        //1.读取books.xml文件
        SAXReader saxReader=new SAXReader();
        Document document = saxReader.read("src/books.xml");
        //2.通过Document对象获取根元素
        Element rootElement = document.getRootElement();
        //3.通过根元素获取book标签对象
        List<Element> books = rootElement.elements("book");

        List<Book> bookList=new ArrayList<>();
        //4.遍历处理每个book标签转换为Book类
        for(Element e:books){
            //asXML()把标签对象转为标签字符串
           // System.out.println(e.asXML());
            Element name = e.element("name");
            //System.out.println(name.asXML());
            //getText()获取标签文本内容
            String nameText=name.getText();
            //elementText直接获取指定标签里的文本内容
            String priceText=e.elementText("price");
            String authorText=e.elementText("author");
            String sn=e.attributeValue("id");
            System.out.println(sn);
            Book book=new Book();
            book.setSn(sn);
            book.setAuthor(authorText);
            book.setName(nameText);
            book.setPrice(new BigDecimal(priceText));
            bookList.add(book);
        }
        System.out.println(bookList);
    }

    public static void main(String[] args) throws DocumentException {
        String projectRoot = System.getProperty("user.dir");
        System.out.println(projectRoot);
        //1.读取books.xml文件
        SAXReader saxReader=new SAXReader();
        Document document = saxReader.read("src/books.xml");
        //2.通过Document对象获取根元素
        Element rootElement = document.getRootElement();
        //3.通过根元素获取book标签对象
        List<Element> books = rootElement.elements("book");

        List<Book> bookList=new ArrayList<>();
        //4.遍历处理每个book标签转换为Book类
        for(Element e:books){
            //asXML()把标签对象转为标签字符串
            // System.out.println(e.asXML());
            Element name = e.element("name");
            //System.out.println(name.asXML());
            //getText()获取标签文本内容
            String nameText=name.getText();
            //elementText直接获取指定标签里的文本内容
            String priceText=e.elementText("price");
            String authorText=e.elementText("author");
            String sn=e.attributeValue("id");
            System.out.println(sn);
            Book book=new Book();
            book.setSn(sn);
            book.setAuthor(authorText);
            book.setName(nameText);
            book.setPrice(new BigDecimal(priceText));
            bookList.add(book);
        }
        System.out.println(bookList);
    }
}

上面@Test可以执行,main方法找不到文件的原因

这是因为在测试中，测试运行器可能会设置不同的当前工作目录（working directory）。