Jaxb基本使用

一、简介

    Jaxb(Java Architecture for XML Binding)是可以根据xml schema产生java类，也可以把java对象写入xml文件中的技术。

    JAXB 2.0是JDK 1.6的组成部分。JAXB 2.2.3是JDK 1.7的组成部分，包括以下几个重要的Interface和Class

    1. JAXBContext 是应用的入口，用来管理Java/xml的绑定信息

    2. Marshaller 由Java对象序生成xml数据

    3. Unmarshaller 由xml数据生成Java对象

二、简单使用示例

package jaxbTest;

//import ...

@XmlRootElement(name="Customer")

@XmlAccessorType(XmlAccessType.FIELD)

public class Customer {

    @XmlAttribute

    private Integer id;

    @XmlElement

    private String name;

    @XmlElement

    private Integer age;

    @XmlElement

    private List<String> accountIds;

    //getter,setter and toString...

    }

    

package jaxbTest;

import java.io.File;

import java.util.ArrayList;

import java.util.List;

import javax.xml.bind.JAXBContext;

import javax.xml.bind.JAXBException;

import javax.xml.bind.Marshaller;

import javax.xml.bind.Unmarshaller;

public class JaxbDemo {

    private static JAXBContext jaxbContext = null;

    static {

        try {

            jaxbContext = JAXBContext.newInstance(Customer.class);

        } catch (JAXBException e) {

            e.printStackTrace();

        }

    }

    public static void object2Xml(Customer customer, File file) throws JAXBException {

        Marshaller marshaller = jaxbContext.createMarshaller();

        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

        marshaller.marshal(customer, file);

        marshaller.marshal(customer, System.out);

    }

    public static Customer xml2Object(File file) throws JAXBException {

        Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();

        return (Customer)unmarshaller.unmarshal(file);

    }

    public static void testMarshaller() throws JAXBException {

        Customer customer = new Customer();

        customer.setId(1);

        customer.setName("Kent");

        customer.setAge(25);

        List<String> accountIds = new ArrayList<String>();

        accountIds.add("123");

        accountIds.add("456");

        accountIds.add("789");

        customer.setAccountIds(accountIds);

        File file = new File("F:\\test\\jaxb_test.xml");

        JaxbDemo.object2Xml(customer, file);

    }

    public static void testUnmarshaller() throws JAXBException {

        File file = new File("F:\\test\\jaxb_test.xml");

        Customer customer = JaxbDemo.xml2Object(file);

        System.out.println(customer);

    }

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

        testMarshaller();

        //testUnmarshaller();

    }

}

调用testMarshaller()结果生成xml数据

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<Customer id="1">

    <name>Kent</name>

    <age>25</age>

    <accountIds>123</accountIds>

    <accountIds>456</accountIds>

    <accountIds>789</accountIds>

</Customer>

调用testUnmarshaller()生成java对象

Customer [id=1, name=Kent, age=25, accountIds=[123, 456, 789]]