Spring IOC（通过实例介绍，属性与构造方法注入）

概括说明：下面通过实例介绍下属性方法注入、构造方法注入

1、源码结构图

2、代码介绍

（1）、Dao接口 ：UserDAO

（2）、Dao接口实现：UserDAOImpl

（3）、实体类：User

（4）、服务层接口：UserService

（5）、服务层接口实现：UserServiceImpl

（6）、测试主类：UserServiceTest

3、源代码

（1）、Dao接口 ：UserDAO

package com.northeasttycoon.dao;

import com.northeasttycoon.model.User;

/**
 * @author tycoon
 */
public interface UserDAO {

	public void save(User user);
}

（2）、Dao接口实现：UserDAOImpl

package com.northeasttycoon.dao.impl;

import com.northeasttycoon.dao.UserDAO;
import com.northeasttycoon.model.User;
/**
 * @author tycoon
 */
public class UserDAOImpl implements UserDAO {

	// 保存数据方法
	public void save(User user) {

		System.out.println("username:"+user.getUsername() +" ,userpassword:"+user.getPassword()+ " ,saved in Oracle!");
		System.out.println(user.getUsername() + " saved in DB2!");
	}
}

（3）、实体类：User

package com.northeasttycoon.model;

/**
 * 用户实体类
 * @author tycoon
 *
 */
public class User {

	private String username;
	private String password;

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}
}

（4）、服务层接口：UserService

package com.northeasttycoon.service;

import com.northeasttycoon.model.User;

/**
 * 服务层接口
 * @author tycoon
 *
 */
public interface UserService {

	//处理新增用户业务逻辑
	public void add(User user);
}

（5）、服务层接口实现：UserServiceImpl

package com.northeasttycoon.service;

import com.northeasttycoon.dao.UserDAO;
import com.northeasttycoon.model.User;

/**
 * 服务层接口实现类
 * @author tycoon
 */
public class UserServiceImpl {

    // 属性注册方式实现方法注入
    private UserDAO userDAO;

    public void add(User user) {
        userDAO.save(user);
    }

    public UserDAO getUserDAO() {
        return userDAO;
    }

    public void setUserDAO(UserDAO userDAO) {
        this.userDAO = userDAO;
    }

    // 构造方法注入
    // public UserServiceImpl(UserDAO userDAO) {
    // super();
    // this.userDAO = userDAO;
    // }
}

（6）、测试主类：UserServiceTest

package com.northeasttycoon.service.test;

import org.apache.log4j.Logger;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.northeasttycoon.model.User;
import com.northeasttycoon.service.UserServiceImpl;

// 测试类
public class UserServiceTest {

	final static Logger logger = Logger.getLogger(UserServiceTest.class);

	@Test
	public void testAdd() throws Exception {
		logger.info("insert sucessful start! ");
		// 创建容器
		ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
		UserServiceImpl service = (UserServiceImpl) ctx.getBean("userService");

		// 创建U实例
		User u = new User();
		u.setUsername("东北大亨");
		u.setPassword("123456");
		service.add(u);
		logger.info("insert sucessful end! ");
	}
}

（7）、配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
  <bean id="u" class="com.northeasttycoon.dao.impl.UserDAOImpl"/>
  <bean id="userService" class="com.northeasttycoon.service.UserServiceImpl">
  <!--  通过property元素 把U实例注册到userDAO中   -->
  	 <property name="userDAO">
  	 	<ref bean="u"/>
  	 </property>
  	   <!--  通过构造方法 把U实例注册到userDAO中   -->
 <!--<constructor-arg>
			<ref bean="u"/>
	 </constructor-arg>-->
  </bean>
</beans>

（8）、测试结果截图