Spring IOC容器-注解的方式【更简化】

----更加简化的版本

UserAction.java

import javax.annotation.Resource;

import org.springframework.stereotype.Component;
import org.springframework.stereotype.Controller;

//@Component("userAction")  // 加入IOC容器

//@Component

@Controller  // 控制层的组件
public class UserAction {

	@Resource
	private UserService userService;

	public String execute() {
		userService.save();
		return null;
	}
}

UserService.java

import javax.annotation.Resource;

import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;

//@Component("userService")  // userService加入ioc容器

//@Component

@Service   // 表示业务逻辑层的组件
public class UserService {

//	@Resource	//  根据类型查找 【在容器中要确保该类型只有一个变量】

	@Resource(name = "userDao")  // 根据名称查找
	private UserDao userDao;  // 去容器中招UserDao类型的变量，找到后就赋值

	public void save() {
		userDao.save();
	}
}

UserDao.java

import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;

// 把当前对象加入ioc容器
//@Component("userDao")   //  相当于bean.xml 【<bean id=userDao class=".." />】

//@Component  // 加入ioc容器的UserDao对象的引用名称， 默认与类名一样， 且第一个字母小写

//@Repository   // 在持久层可以选择用这个注解
public class UserDao {

	public UserDao(){
		System.out.println("UserDao.UserDao()");
	}

	public UserDao(int id){
		System.out.println("UserDao.UserDao(int id)" + id);
	}

	public void save() {
		System.out.println("zengmg:保存用户!!!");
	}
}

bean.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:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        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">

	<!-- 开启注解扫描 -->
	<context:component-scan base-package="zengmg.e_anno2"></context:component-scan>

	<bean id="userDao" class="zengmg.UserDao" scope="prototype">
	</bean>

</beans>   

测试代码：

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class App {

	// 创建容器对象
	private ApplicationContext ac =
		new ClassPathXmlApplicationContext("zengmg/e_anno2/bean.xml");

	@Test
	public void testExecuteAction() {
		// 从容器中获取Action
		UserAction userAction = (UserAction) ac.getBean("userAction");
		userAction.execute();
	}
}