spring 通过注解 注入
1. 需要在applicationContext.xml 启动注解注入的方式，添加配置选项，如下：
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xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">
?完整的applicationContext.xml：
<?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:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"> <context:annotation-config/> <!-- 定义使用注解注入 --> <context:component-scan base-package="com.spring"/><!--自动搜索自定包下的类进行注解注入--></beans>
2. 对类进行注解注入
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?? 如何对需要注解的类进行标识，分为两种方法：
?? (1). 通用方法：
?? @Component("别名")?
?? @Scope("prototype")??? //多例(默认是单例)
?? 通用方法对所有的类都可用，如action,service,dao，但是不推荐使用，因在这样不好区分，代码可读性不好。
?? (2).特殊类注解(这种方法是spring推荐的)
?? action??类:???? @Controller("别名")
?? service 类:??? @Service("别名")
?? dao????? 类:??? @Repository("别名")
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3. 实例代码
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?? UserAction：
package com.spring.action;import javax.annotation.Resource;import org.springframework.context.annotation.Scope;import org.springframework.stereotype.Controller;import com.spring.dao.UserDao;import com.spring.service.UserService;@Controller("userAction")@Scope("prototype") //多例模式public class UserAction {@Resource(name="userService") //通过注解得到UserService对象private UserService us;@Resource(name="UserDao") //通过注解得到UserDao对象private UserDao dao;public void run(){System.out.println("UserAction running......");us.runService();dao.addUser("admin");}}?
? UserService:
package com.spring.service;import org.springframework.stereotype.Service;@Service("userService")public class UserService {public void runService(){System.out.println("user service running......");}}?
UserDao:
package com.spring.dao;import org.springframework.stereotype.Repository;@Repository("UserDao")public class UserDao {public void addUser(String username){System.out.println(username+"添加成功");}}?
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