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
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