java学习之路----spring探索2---注解.pdf

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java学习之路----spring探索2---注解
分类: javase 2013-12-01 22:35 195人阅读评论(0) 收藏举报
前面章节:
第一节:模拟spring
http://blog./javastudyr/article/details/17055743
第二节:spring ioc     http://blog./javastudyr/article/details/17057699
开始学习注解

<?xml version= "" encoding ="UTF-8"?>
<beans xmlns="ema/beans"
 xmlns:xsi="1/XMLSchema-
instance" xmlns:context="e
ma/context"
 xsi:schemaLocation="
ema/beans
ema/beans/spring-
beans-
ema/context

ema/context/spring-
context-">

<!-- 这里必须写这个才能注入成功-->
<context:annotation-config />
<bean name="userDAO" class="
pl" >
 <property name= "daoId" value ="1"></ property>
</bean >
<bean id="userService" class="
ice" >
 <!-- <property name="userDAO" bean="u" />修改为下
面的样子-->
<!-- <property name= "userDAO" ref = "userDAO" />
-->
1
</bean >
</beans>   
2. <context:annotation-config />的作用
它的作用是初始化了
AutowiredAnnotationBeanPostProcessor, CommonAnnotationBeanPostProcessor,PersistenceAnnot
ationBeanPostProcessor, as well as the aforementioned RequiredAnnotationBeanPostProcessor
记住这些就是用来处理我们注解的bean
(通过byType来注入的)   注入
public class UserService {

private UserDAO userDAO;

public UserDAO getUserDAO() {
 return userDAO ;
}
***@Autowired
public void setUserDAO(UserDAO userDAO) {
 this .userDAO = userDAO;
}
public void addUser(User user ){
 (user);

};
}
 最好写在setter 上面,如果写在 private UserDAO userDAO;上面,破换封装性
4.***@Resource(默认是byName方法来注入)注入
2
public class UserService {

private UserDAO userDAO; //现在是这样,通过配置文件来实
例化

public UserDAO getUserDAO() {
 return userDAO ;
}
***@Resource
public void setUserDAO(UserDAO userDAO) {
 this .userDAO = userDAO;
}
public void addUser(User user ){
 (user);

};
}
推荐使用***@Resource
ponent(组件)注解
在spring 中如果不想自己写bean,也可以用组件来让spring 为你写
代码:
          在userDAOIm