[email protected]@resource的使用详解编程语言

@Component(“”)[email protected](name=””)的使用:

spring的配置文件配置：

  <?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:aop=“http://www.springframework.org/schema/aop”

       xmlns:tx=“http://www.springframework.org/schema/tx”

       xsi:schemaLocation=“http://www.springframework.org/schema/beans

           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd

           http://www.springframework.org/schema/context

         http://www.springframework.org/schema/context/spring-context-3.0.xsd

         http://www.springframework.org/schema/tx

     http://www.springframework.org/schema/tx/spring-tx-3.0.xsd

     http://www.springframework.org/schema/aop

     http://www.springframework.org/schema/aop/spring-aop-3.0.xsd”>

    

<!– 扫描com.test 包，[email protected]/@Component等–>

<context:component-scan base-package=“com.test” />

<beans>

配置<context:component-scan base-package=”com.test” />解析：

使用ClassPathXmlApplicationContext(“bean.xml”)初始化bean.xml的时候，或者说初始化spring配置文件的时候，会自动扫描com.test下的所有包,[email protected]，则将该类初始化为一个对象，[email protected](“name”)中指明的name,若不指明，则默认为类的名字首字母小写；当调用ctx.getBean(“userService”)，时，则查看容器是否有一个名字为userService；如有则在初始化这个类得过程中，[email protected](name=”u”);则查看容器是否有名字叫u的bean,若有则将u注入到方法参数中，而后参数就会传人方法内，当然也就注入了成员变量里：

UserService.java文件中使用：

@Component(“userService”)

public class UserService {

    private UserDAO userDAO = new UserDAOImpl();

    private UserLogDAO userLogDAO;

 

    public UserDAO getUserDAO() {

       return userDAO;

    }

    public UserLogDAO getUserLogDAO() {

       return userLogDAO;

    }

    @Resource(name=“ulog”)

    public void setUserLogDAO(UserLogDAO userLogDAO) {

       this.userLogDAO = userLogDAO;

    }

    @Resource(name=“u”)

    public void setUserDAO(UserDAO userDAO) {

       this.userDAO = userDAO;

 

    }

UserDAOImpl.java中使用：

 

  @Component(“u”)

public class UserDAOImpl implements UserDAO {

    private SessionFactory  sessionFactory;

   

 

    public SessionFactory getSessionFactory() {

       return sessionFactory;

    }

 

    @Resource

    public void setSessionFactory(SessionFactory sessionFactory) {

       this.sessionFactory = sessionFactory;

    }

    @Override

    public void save(User u) {

           Session s=sessionFactory.openSession();//.getCurrentSession();

           //s.beginTransaction();

           s.save(u);

       System.out.println(“a user save,XXXX!”);

    }

}

[email protected]@resource注解，相当于spring使用了如下的配置：

  这样就可以省去之前在bean中所写的:

<!– 

  <bean id=“u” class=“com.test.dao.impl.UserDAOImpl”>

  </bean>

  <bean id=”UserService” class=”com.test.service.UserService”>

    <property name=”UserDAO” ref=”u” />       

  </bean>