JAXB简单样例 Java API for XML Building

参考网页：http://www.mkyong.com/java/jaxb-hello-world-example/
JAXB完整教程：https://jaxb.java.net/tutorial/
1.JAXB 依赖
maven项目使用JAXB首先需要添加jaxb api和jaxb impl,jaxb core(因为jaxb api 2.2.11 版本之后不再支持annomationReader，详见:http://stackoverflow.com/questions/27046836/why-has-annotationreader-been-removed-from-jaxb-reference-implementation)：
jaxb api的maven dependency可以在这里找到：http://mvnrepository.com/artifact/javax.xml/jaxb-api
jaxb impl的maven dependency可以在这里找到：http://mvnrepository.com/artifact/com.sun.xml.bind/jaxb-impl
jaxb core的maven dependency可以在这里找到：http://mvnrepository.com/artifact/com.sun.xml.bind/jaxb-core
这里使用最新的版本，添加如下代码到pom.xml的dependencies当中：

<!-- http://mvnrepository.com/artifact/com.sun.xml.bind/jaxb-core --><dependency>    <groupId>com.sun.xml.bind</groupId>    <artifactId>jaxb-core</artifactId>    <version>2.2.11</version></dependency><!-- http://mvnrepository.com/artifact/javax.xml/jaxb-api --><dependency>    <groupId>javax.xml</groupId>    <artifactId>jaxb-api</artifactId>    <version>2.1</version></dependency><!-- http://mvnrepository.com/artifact/com.sun.xml.bind/jaxb-impl --><dependency>    <groupId>com.sun.xml.bind</groupId>    <artifactId>jaxb-impl</artifactId>    <version>2.2.11</version></dependency>

2.JAXB注释
需要进行xml转换的类必须用JAXB注释（JAXB annotation）进行注释。

package com.mypackage;import javax.xml.bind.annotation.XmlAttribute;import javax.xml.bind.annotation.XmlElement;import javax.xml.bind.annotation.XmlRootElement;@XmlRootElementpublic class Customer {    String name;    int age;    int id;    public String getName() {        return name;    }    @XmlElement    public void setName(String name) {        this.name = name;    }    public int getAge() {        return age;    }    @XmlElement    public void setAge(int age) {        this.age = age;    }    public int getId() {        return id;    }    @XmlAttribute    public void setId(int id) {        this.id = id;    }    @Override    public String toString() {        return "Customer [name=" + name + ", age=" + age + ", id=" + id + "]";    }}

3.将对象转换成XML
JAXB编组（marshall）对象成XML。

package com.mypackage;import java.io.File;import javax.xml.bind.JAXBContext;import javax.xml.bind.JAXBException;import javax.xml.bind.Marshaller;public class JAXBMarshallExample {    public static void main(String[] args) {        Customer customer = new Customer();        customer.setId(1000);        customer.setName("moon");        customer.setAge(18);                try {            File file = new File("C:\\file.xml");            JAXBContext jaxbContext = JAXBContext.newInstance(Customer.class);            Marshaller jaxbMarshaller = jaxbContext.createMarshaller();                        // output pretty printed            jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);                        jaxbMarshaller.marshal(customer, file);            jaxbMarshaller.marshal(customer, System.out);        } catch (JAXBException e) {            e.printStackTrace();        }    }}

输出结果：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><customer id="1000">    <age>18</age>    <name>moon</name></customer>

4.将XML转换成对象
JAXB解组(unmarshall)XML成对象。

package com.mypackage;import java.io.File;import javax.xml.bind.JAXBContext;import javax.xml.bind.JAXBException;import javax.xml.bind.Unmarshaller;public class JAXBUnmarshallExample {    public static void main(String[] args) {        try {            File file = new File("C:\\file.xml");            JAXBContext jaxbContext = JAXBContext.newInstance(Customer.class);                        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();            Customer customer = (Customer) jaxbUnmarshaller.unmarshal(file);            System.out.println(customer);        } catch (JAXBException e) {            e.printStackTrace();        }    }}

程序输出：

Customer [name=moon, age=18, id=1000]