springMVC整合JAXB[通俗易懂]

一.背景

由于项目中要用到将Java对象转为xml返回给调用者。选择使用JAXB，由于它是JDK自带的。不须要引入其它Jar包

它提供了高速而简便的方法将xml和对象互转的方法。

二.重要Class和Interface：

JAXBContext：应用的入口。用于管理XML/Java绑定信息。
Marshaller：将Java对象序列化为XML数据。
Unmarshaller：将XML数据反序列化为Java对象。
JDK中JAXB相关的重要Annotation：

三.重要的Annotation：
@XmlType，将Java类或枚举类型映射到XML模式类型

@XmlAccessorType  定义映射这个类中的何种类型须要映射到XML。可接收四个參数，各自是：

XmlAccessType.FIELD：映射这个类中的全部字段到XML

XmlAccessType.PROPERTY：映射这个类中的属性（get/set方法）到XML

XmlAccessType.PUBLIC_MEMBER：将这个类中的全部public的field或property同一时候映射到XML（默认）

XmlAccessType.NONE：不映射

@XmlAccessorOrder，控制JAXB 绑定类中属性和字段的排序。
@XmlJavaTypeAdapter，使用定制的适配器（即扩展抽象类XmlAdapter并覆盖marshal()和unmarshal()方法）。以序列化Java类为XML。

@XmlElementWrapper ，对于数组或集合（即包括多个元素的成员变量）。生成一个包装该数组或集合的XML元素（称为包装器）。

@XmlRootElement。将Java类或枚举类型映射到XML元素。

@XmlElement。将Java类的一个属性映射到与属性同名的一个XML元素。
@XmlAttribute，将Java类的一个属性映射到与属性同名的一个XML属性。

四.代码实现：

1. 代码结构图

2. spring配置：

<?xml version="1.0" encoding="UTF-8"?
><beans xmlns="http://www.springframework.org/schema/beans"	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"	xmlns:context="http://www.springframework.org/schema/context"	xmlns:mvc="http://www.springframework.org/schema/mvc"	xsi:schemaLocation="http://www.springframework.org/schema/mvc 		http://www.springframework.org/schema/mvc/spring-mvc.xsd		http://www.springframework.org/schema/beans 		http://www.springframework.org/schema/beans/spring-beans.xsd		http://www.springframework.org/schema/context 		http://www.springframework.org/schema/context/spring-context.xsd">		<!-- 加入注解驱动 -->	<mvc:annotation-driven />		<!-- 默认扫描的包路径 -->	<context:component-scan base-package="com.zdp" />        <!-- 视图解析器 -->    <bean class="org.springframework.web.servlet.view.BeanNameViewResolver">        <property name="order" value="1"/>    </bean>        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">          <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>      </bean>  		<bean name="jaxb2MarshallingView" class="org.springframework.web.servlet.view.xml.MarshallingView">		<constructor-arg>			<bean class="org.springframework.oxm.jaxb.Jaxb2Marshaller">				<property name="classesToBeBound">					<array>						<value>com.zdp.domain.User</value>						<value>com.zdp.domain.ListBean</value>						<value>com.zdp.domain.MapBean</value>					</array>				</property>			</bean>		</constructor-arg>	</bean></beans>

3. UserBean (ListBean及MapBean请在源代码中查看)

@XmlRootElement(name = "user")
@XmlAccessorType(XmlAccessType.PUBLIC_MEMBER)
public class User {
	@XmlAttribute(name = "id")
	public String id;
	
	@XmlAttribute(name = "name")
	public String name;
	
	@XmlAttribute(name = "age")
	public int age;
	
	@XmlAttribute(name = "sex")
	public String sex;
	
	@XmlElement(name = "address")
	public String address;
	
	@XmlElement(name = "Account")
	public Account account;

	public static class Account {
		@XmlAttribute(name = "username")
		public String username;

		@XmlValue
		public String password;

		public Account() {
		}

		public Account(String username, String password) {
			this.username = username;
			this.password = password;
		}
	}
	
	@XmlElement(name = "Cards")
	public Cards cards;
	
	public static class Cards {
		@XmlElement(name = "card")
		public List<String> cards;

		public Cards() {
		}

		public Cards(List<String> cards) {
			this.cards = cards;
		}
	}
	
	public User(){}

}

4. Controller

@Controller
public class JAXBController {
	/**
	 * 将对象转为xml
	 */
	@RequestMapping("/object2xml")
	public ModelAndView object2xml(){
		ModelAndView mav = new ModelAndView("jaxb2MarshallingView");
		User user = new User();
		user.name = "zhangsan";
		user.id = "1";
		user.address = "shenzhen";
		user.age = 20;
		user.sex = "man";
		
		user.account = new Account("zhang", "abc123");
		
		List<String> cards = new ArrayList<String>();
		cards.add("gonghang");
		cards.add("jianhang");
		user.cards = new Cards(cards);
		
		mav.addObject(user);
		return mav;
	}
	
	/**
	 * 将list转为xml
	 */
	@RequestMapping("/list2xml")
	public ModelAndView list2xml(){
		ModelAndView mav = new ModelAndView("jaxb2MarshallingView");
		List<User> userList = new ArrayList<User>();
		for(int i = 0; i < 2; i++){
			User user = new User();
			user.name = "zhangsan" + i;
			user.id = "1";
			user.address = "shenzhen";
			user.age = 20;
			user.sex = "man";
			user.account = new Account("zhang" + i, "abc123");
			List<String> cards = new ArrayList<String>();
			cards.add("gonghang" + i);
			cards.add("jianhang" + i);
			user.cards = new Cards(cards);
			
			userList.add(user);
		}
		
		ListBean listBean = new ListBean();
		listBean.setList(userList);
		mav.addObject(listBean);
		return mav;
	}
	
	
	/**
	 * 将map转为xml
	 */
	@RequestMapping("/map2xml")
	public ModelAndView map2xml(){
		ModelAndView mav = new ModelAndView("jaxb2MarshallingView");
		MapBean mapBean = new MapBean();
	    HashMap<String, User> map = new HashMap<String, User>();
	    
	    for(int i = 0; i < 2; i++){
			User user = new User();
			user.name = "zhangsan" + i;
			user.id = "1";
			user.address = "shenzhen";
			user.age = 20;
			user.sex = "man";
			user.account = new Account("zhang" + i, "abc123");
			List<String> cards = new ArrayList<String>();
			cards.add("gonghang" + i);
			cards.add("jianhang" + i);
			user.cards = new Cards(cards);

			map.put("1", user);
		}
	    
	    mapBean.setMap(map);
	    mav.addObject(mapBean);
		return mav;
	}
}

5. 測试：浏览器输入http://localhost/spring_jaxb/object2xml

<?
xml version="1.0" encoding="UTF-8"?
><user sex="man" age="20" name="zhangsan" id="1"><address>shenzhen</address><Account username="zhang">abc123</Account><Cards><card>gonghang</card><card>jianhang</card></Cards></user>

6. 源代码：http://download.csdn.net/detail/zdp072/8074493