JAXB POJO to XML / XML to POJO

JAXB(Java Architecture for XML Binding)是讓JAVA將Java Object to XML / XML to Java Object



Main.java：

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import java.io.File;

public class Main {
    private final static File FILE = getFILE() ;

    private static File getFILE() {
        final String PATH = String.format("%stest.xml", Main.class.getClassLoader().getResource("").getPath());
        final File FILE = new File(PATH);
        return FILE;
    }

    public static void main(String[] args) {
        //write
        classToXML();
        //read
        xmlToClass();
    }

    private static void classToXML() {
        Transcript transcript = new Transcript()
                .addStudentTolist(new Student("王曉明", new Ch(99), new En(50), new Math(100)))
                .addStudentTolist(new Student("你好嗎", new Ch(69), new En(90), new Math(10)));

        try {
            JAXBContext context = JAXBContext.newInstance(new Class[]{Transcript.class, Ch.class, En.class, Math.class, Transcript.class});
            Marshaller marshaller = context.createMarshaller();
            marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");
            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, false);
            marshaller.marshal(transcript, FILE);
            System.out.println("Output test.xml done");
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }

    private static void xmlToClass() {
        Transcript transcript = null;
        try {
            JAXBContext context = JAXBContext.newInstance(new Class[]{Transcript.class, Ch.class, En.class, Math.class, Transcript.class});
            Unmarshaller unmarshaller = context.createUnmarshaller();
            transcript = (Transcript) unmarshaller.unmarshal(FILE);
            for (Student student : transcript.getList()) {
                System.out.printf("name:%s ch:%d en:%d math:%d\n",
                        student.getName(),
                        student.getCh().getScore(),
                        student.getEn().getScore(),
                        student.getMath().getScore());
            }
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }
}

Score.java：

import javax.xml.bind.annotation.*;

@XmlRootElement(name = "score")
@XmlAccessorType(XmlAccessType.FIELD)
public abstract class Score {
    @XmlValue
    private Integer score;

    protected Score() {
    }

    protected Score(Integer score) {
        this.score = score;
    }

    protected Score score(Integer score) {
        this.score = score;
        return this;
    }

    public void setScore(Integer score) {
        this.score = score;
    }

    public Integer getScore() {
        return score;
    }

}

Ch.java：

public class Ch extends Score {
    public Ch() {
        super();
    }

    public Ch(Integer score) {
        super(score);
    }

    public Ch score(Integer score) {
        return (Ch) super.score(score);
    }
}

En.java：

public class En extends  Score{
    public En() {
        super();
    }

    public En(Integer score) {
        super(score);
    }

    public En score(Integer score) {
        return (En) super.score(score);
    }
}

Math.java：

public class Math extends Score {
    public Math() {
        super();
    }

    public Math(Integer score) {
        super(score);
    }

    public Math score(Integer score) {
        return (Math)super.score(score);
    }
}

Student.java：

import javax.xml.bind.annotation.*;

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Student {
    private String name;
    private Ch ch;
    private En en;
    private Math math;

    public Student() {
    }

    public Student(String name) {
        this.name = name;
    }

    public Student(String name, Ch ch, En en, Math math) {
        this.name = name;
        this.ch = ch;
        this.en = en;
        this.math = math;
    }

    public Student name(String name) {
        this.name = name;
        return this;
    }

    public Student ch(Ch ch) {
        this.ch = ch;
        return this;
    }

    public Student en(En en) {
        this.en = en;
        return this;
    }

    public Student math(Math math) {
        this.math = math;
        return this;
    }

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

    public void setCh(Ch ch) {
        this.ch = ch;
    }

    public void setEn(En en) {
        this.en = en;
    }

    public void setMath(Math math) {
        this.math = math;
    }

    public String getName() {
        return name;
    }

    public Ch getCh() {
        return ch;
    }

    public En getEn() {
        return en;
    }

    public Math getMath() {
        return math;
    }
}

Transcript.java：

import javax.xml.bind.annotation.*;
import java.util.ArrayList;
import java.util.List;

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Transcript {
    @XmlElement(name = "Student")
    private List<Student> list = new ArrayList<Student>();

    public Transcript() {
    }

    public Transcript(List<Student> list) {
        this.list = list;
    }

    public Transcript addStudentTolist(Student student) {
        this.list.add(student);
        return this;
    }

    public void setList(List<Student> list) {
        this.list = list;
    }

    public List<Student> getList() {
        return list;
    }
}

輸出結果：

參考資料：
https://docs.oracle.com/javase/tutorial/jaxb/intro/index.html