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>
