使用JAXB将Java对象序列化为带属性的XML文件

<?xml version="1.0" encoding="UTF-8"?>
<persons>
    <person name="Nick" birthday="09.03.1814"/>
    <person surname="Sd" name="aaa" birthday="09.03.1814"/>
</persons>

<dtoPerson>
    <birthday>09.03.1814</birthday>
    <name>aaa Sd</name>
</dtoPerson>

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlRootElement; // 如果Person可以单独作为根元素，则需要

/**
 * 表示XML中的<person>元素，其数据通过属性表示。
 */
@XmlAccessorType(XmlAccessType.FIELD) // 指定JAXB通过字段访问数据
public class Person {

    @XmlAttribute(name = "name") // 将此字段映射为XML属性"name"
    private String name;

    @XmlAttribute(name = "birthday") // 将此字段映射为XML属性"birthday"
    private String birthday;

    @XmlAttribute(name = "surname") // 可选字段，映射为XML属性"surname"
    private String surname;

    // JAXB需要一个无参构造函数
    public Person() {
    }

    public Person(String name, String birthday, String surname) {
        this.name = name;
        this.birthday = birthday;
        this.surname = surname;
    }

    // Getters and Setters
    public String getName() {
        return name;
    }

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

    public String getBirthday() {
        return birthday;
    }

    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }

    public String getSurname() {
        return surname;
    }

    public void setSurname(String surname) {
        this.surname = surname;
    }

    @Override
    public String toString() {
        return "Person{" +
               "name='" + name + '\'' +
               ", birthday='" + birthday + '\'' +
               ", surname='" + surname + '\'' +
               '}';
    }
}

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import java.util.ArrayList;
import java.util.List;

/**
 * 表示XML中的<persons>根元素，包含一个Person对象的列表。
 */
@XmlRootElement(name = "persons") // 将此类映射为XML根元素"persons"
@XmlAccessorType(XmlAccessType.FIELD) // 指定JAXB通过字段访问数据
public class Persons {

    @XmlElement(name = "person") // 将列表中的每个元素映射为XML子元素"person"
    private List<Person> personsList;

    // JAXB需要一个无参构造函数
    public Persons() {
        this.personsList = new ArrayList<>();
    }

    public Persons(List<Person> personsList) {
        this.personsList = personsList;
    }

    // Getters and Setters
    public List<Person> getPersonsList() {
        return personsList;
    }

    public void setPersonsList(List<Person> personsList) {
        this.personsList = personsList;
    }

    public void addPerson(Person person) {
        if (this.personsList == null) {
            this.personsList = new ArrayList<>();
        }
        this.personsList.add(person);
    }
}

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import java.io.File;
import java.util.ArrayList;
import java.util.List;

public class XmlGenerator {

    public static void main(String[] args) {
        // 1. 准备数据
        List<Person> personData = new ArrayList<>();
        personData.add(new Person("Nick", "09.03.1814", null)); // 没有surname
        personData.add(new Person("Alice", "15.06.1990", "Smith"));
        personData.add(new Person("Bob", "22.11.1985", "Johnson"));

        // 2. 创建根对象 (Persons) 并填充数据
        Persons personsWrapper = new Persons(personData);

        try {
            // 3. 创建JAXBContext实例，指定根元素类
            // JAXBContext需要知道哪些类参与到XML的生成中
            JAXBContext jaxbContext = JAXBContext.newInstance(Persons.class);

            // 4. 创建Marshaller实例
            Marshaller marshaller = jaxbContext.createMarshaller();

            // 5. 配置Marshaller属性
            // 设置XML输出格式化，使其具有缩进和换行，提高可读性
            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
            // 可选：设置XML头编码
            marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");

            // 6. 执行编组操作
            // 输出到控制台
            System.out.println("--- Generated XML (to console) ---");
            marshaller.marshal(personsWrapper, System.out);

            // 输出到文件
            File file = new File("persons_with_attributes.xml");
            marshaller.marshal(personsWrapper, file);
            System.out.println("\n--- XML file created successfully ---");
            System.out.println("File path: " + file.getAbsolutePath());

        } catch (JAXBException e) {
            System.err.println("Error during JAXB marshalling: " + e.getMessage());
            e.printStackTrace();
        }
    }
}

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<persons>
    <person name="Nick" birthday="09.03.1814"/>
    <person name="Alice" birthday="15.06.1990" surname="Smith"/>
    <person name="Bob" birthday="22.11.1985" surname="Johnson"/>
</persons>