SpringIOC的應用

導入須要的jar包

配置文件爲:

通常不用註解操做時使用<bean id=" " class=" ">來建立對象

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.2.xsd">
    <!-- 開啓註解 用於激活那些已經在spring容器裏註冊過的bean（不管是經過xml的方式仍是經過package sanning的方式）上面的註解，是一個註解處理工具。-->
    <context:annotation-config></context:annotation-config>
    <bean id="userDao" class="cn.bdqn.dao.impl.UserDaoImpl"></bean>
    <bean id="userService" class="cn.bdqn.service.impl.UserServiceImpl"></bean>
</beans>

測試類中能夠:

@Test
    public void testSpring1(){
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserService userService = (UserService)ac.getBean("userService");
        User u = new User();
        userService.addUser(u);  //運行userServiceimpl(在xml中別名爲userService)中roleShow()方法
}

 

若是徹底使用註解操做,那麼配置文件裏就能夠這樣寫

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.2.xsd">
    <!-- 加入註解掃描  <context:component-scan>除了具
    有<context:annotation-config>的功能以外，
    <context:component-scan>還能夠在指定的package下掃描以及註冊javabean 。-->    
    <context:component-scan base-package="cn.bdqn"></context:component-scan>
</beans>

測試類中能夠:

@Test
    public void testSpring(){
        ApplicationContext ac = new ClassPathXmlApplicationContext("beans-scan.xml");
        User user = (User)ac.getBean("user");
        user.getRole().roleShow();  //運行roleShow()方法
}

使用註解定義bean:

@Component 用於全部使用註解定義bean

@Component("role")   //至關於<bean id="role" class="cn.bdqn.entity.Role"></bean>
public class Role { 

@Repository 用於標註DAO類

@Repository("userDao")  
public class UserDaoImpl implements UserDao{

@Service 用於標註Service類

@Service("userService")
public class UserServiceImpl implements UserService{

@Controller 用戶標註業務類