JAXB实现java转xml的demo【转】

demo1：

转自：http://hbiao68.iteye.com/blog/1958413

下面使用的是JDK自带的类，没有引用任何第三方jar包。

 

Unmarshaller 类使客户端应用程序能够将 XML 数据转换为 Java 内容对象树。

备注：marshal(序列化、排列、整理)

Marshaller 类使客户端应用程序能够将 Java 内容树转换回 XML 数据。

 

package hb.jaxb;

public class Classroom {
    private int id;
    private String name;
    private int grade;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public int getGrade() {
        return grade;
    }

    public void setGrade(int grade) {
        this.grade = grade;
    }

    public Classroom(int id, String name, int grade) {
        super();
        this.id = id;
        this.name = name;
        this.grade = grade;
    }

    public Classroom() {
        super();
    }

}

 

package hb.jaxb;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class Student {
    private int id;
    private String name;
    private int age;
    private Classroom classroom;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public Classroom getClassroom() {
        return classroom;
    }

    public void setClassroom(Classroom classroom) {
        this.classroom = classroom;
    }

    public Student(int id, String name, int age, Classroom classroom) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
        this.classroom = classroom;
    }

    //无参够着函数一定需要，否则JXBContext无法正常解析。
    public Student() {
        super();
    }
}

 

注意：

1、需要转换的model对象一定要添加@XmlRootElement注解，其里面的其他对象则不需要

2、需要转换的model对象一定要有不带参数的构造方法，包括该对象里面引用的对象。

 

package hb.jaxb;

import java.io.StringReader;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import org.junit.Test;

public class TestJaxb {

    @Test
    public void beanToXML() {
        Classroom classroom = new Classroom(1, "软件工程", 4);
        Student student = new Student(101, "张三", 22, classroom);

        try {
            JAXBContext context = JAXBContext.newInstance(Student.class);
            Marshaller marshaller = context.createMarshaller();
            marshaller.marshal(student, System.out);
        } catch (JAXBException e) {
            e.printStackTrace();
        }

    }

    @Test
    public void XMLStringToBean(){
        String xmlStr = "<?xml version=\"1.0 \" encoding=\"UTF-8\" standalone=\"yes\"?><student><age> 22</age><classroom><grade>4< /grade><id>1</id><name>软件工程</name>< /classroom><id>101</id><name>张三</name>< /student>";
        try {
            JAXBContext context = JAXBContext.newInstance(Student.class);
            Unmarshaller unmarshaller = context.createUnmarshaller();
            Student student = (Student)unmarshaller.unmarshal(new StringReader(xmlStr));
            System.out.println(student.getAge());
            System.out.println(student.getClassroom().getName());
        } catch (JAXBException e) {
            e.printStackTrace();
        }

    }
}

 

    JAXB（Java Architecture for XML Binding) 是一个业界的标准，是一项可以根据XML Schema产生Java类的技术。该过程中，JAXB也提供了将XML实例文档反向生成Java对象树的方法，并能将Java对象树的内容重新写到 XML实例文档。从另一方面来讲，JAXB提供了快速而简便的方法将XML模式绑定到Java表示，从而使得Java开发者在Java应用程序中能方便地结合XML数据和处理函数。

 

    JAXBContext 类提供到 JAXB API 的客户端入口点。它提供了管理实现 JAXB 绑定框架操作所需的 XML/Java 绑定信息的抽象，这些操作包括：解组、编组和验证。

 

 

 

 

---

 

demo2：

转自：http://www.blogjava.net/kangdy/archive/2011/11/23/364635.html

code1: colors类  根节点

code1

package com.kangdy.test;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "Colors")
@XmlAccessorType(XmlAccessType.FIELD)
public class Colors {
    
    @XmlElement(name = "red",nillable=true)
    private Red red;
    
    @XmlElement(name = "blue",nillable=true)
    private Blue blue;

    public Red getRed() {
        return red;
    }

    public Blue getBlue() {
        return blue;
    }

    public void setRed(Red red) {
        this.red = red;
    }

    public void setBlue(Blue blue) {
        this.blue = blue;
    }
}

code2:  Red类  子节点

code2

package com.kangdy.test;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "red")
@XmlAccessorType(XmlAccessType.FIELD)
public class Red {
    
    private String value;
    
    @XmlAttribute(name = "att1")
    private String att;
    
    public String getValue() {
        return value;
    }
    
    public void setValue(String value) {
        this.value = value;
    }

    public String getAtt() {
        return att;
    }

    public void setAtt(String att) {
        this.att = att;
    }
    
}

code3:  类 Blue 子节点

code3

package com.kangdy.test;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "blue")
@XmlAccessorType(XmlAccessType.FIELD)
public class Blue {
    private String value;
    
    @XmlAttribute(name = "att2")
    private String att2;
    
    @XmlAttribute(name = "att1")
    private String att;
    
    public String getAtt() {
        return att;
    }

    public void setAtt(String att) {
        this.att = att;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    public String getAtt2() {
        return att2;
    }

    public void setAtt2(String att2) {
        this.att2 = att2;
    }
}

code4: main类

code4

package com.kangdy.test;

import java.io.StringWriter;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;

public class Jaxbtest {
    public static void main(String[] args) throws Exception {

        StringWriter writer = new StringWriter();
        JAXBContext jc = JAXBContext.newInstance(Colors.class);
        Marshaller ma = jc.createMarshaller();
        ma.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        
        Colors colors = new Colors();
        Red red = new Red();
        red.setAtt("att-red");
        red.setValue("red");
        Blue blue = new Blue();
        blue.setValue("blue");
        blue.setAtt("att-blue");
        blue.setAtt2("blue-att2");
        colors.setRed(red);
        colors.setBlue(blue);
        
        ma.marshal(colors, writer);
        System.out.println(writer.toString());

    }
}

运行结果：

结果

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Colors>
    <red att1="att-red">
        <value>red</value>
    </red>
    <blue att1="att-blue" att2="blue-att2">
        <value>blue</value>
    </blue>
</Colors>