Spring----IOC实例

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最新推荐文章于 2024-01-23 23:06:20 发布

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分类专栏： Spring

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本文介绍了Spring框架中两种依赖注入的方式：通过getter/setter方法注入和通过构造器方式注入。通过具体的代码示例展示了如何配置applicationContext.xml文件以及如何进行单元测试。

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Spring----IOC实例

第一种方式：通过getter/setter方法注入：

1、新建一个Java工程，添加spring3.1支持

2、在src下新建com.etc.dao包，新建UserDAO.java类：

package com.etc.dao;

public class UserDAO {
	public void create(){
		System.out.println("create");
	}
}

3、在src下新建com.etc.service包，新建UserService.java类：

package com.etc.service;

import com.etc.dao.UserDAO;

public class UserService {
	private UserDAO userDAO;
	public void doCreate(){
		userDAO.create();
	}
	public UserDAO getUserDAO() {
		return userDAO;
	}
	public void setUserDAO(UserDAO userDAO) {
		this.userDAO = userDAO;
	}
	
}

4、配置applicationContext.xml文件：

<?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"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">
<bean name="userService" class="com.etc.service.UserService">
	<property name="userDAO" ref="userDAO"></property>
</bean>
<!-- 
	   相当于：
	 UserService userService = new UserService();
	 UserDAO userDAO = new UserDAO();
	 userService.setUserDAO(userDAO);
 -->
<bean name="userDAO" class="com.etc.dao.UserDAO"></bean>
</beans>

5、在工程下新建test源文件夹，在文件夹下新建com.etc.test包，在包下新建UserServiceTest.java测试类如下：

package com.etc.test;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.etc.service.UserService;
public class UserServiceTest {
	@Test
	public void test(){
		ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
		UserService userService = (UserService) context.getBean("userService");
		userService.doCreate();
	}
}

第二种方式：通过构造器方式注入：

1、新建一个java工程，添加spring3.1支持

2、新建UserDAO.java类：

package com.etc.dao;

public class UserDAO {
	public void create(){
		System.out.println("create");
	}
}

3、新建UserService.java类：

package com.etc.service;

import com.etc.dao.UserDAO;

public class UserService {
	private UserDAO userDAO;
	public UserService(UserDAO userDAO){
		this.userDAO = userDAO;
	}
	public void doCreate(){
		userDAO.create();
	}

}

4、配置applicationContext.xml文件：

<?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"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">
<bean name="userService" class="com.etc.service.UserService">
	<!-- <property name="userDAO" ref="userDAO"></property> -->
	<constructor-arg index="0" ref="userDAO"></constructor-arg>
</bean>
<!-- 
	   相当于：
	 UserDAO userDAO = new UserDAO();
	 UserService userService = new UserService(userDAO);
 -->
<bean name="userDAO" class="com.etc.dao.UserDAO"></bean>
</beans>

5、新建UserServiceTest.java测试类：

package com.etc.test;

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

import com.etc.service.UserService;

public class UserServiceTest {
	@Test
	public void test(){
		ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
		UserService userService = (UserService) context.getBean("userService");
		userService.doCreate();
	}
}