Spring_IOC_自动装配

1.目录结构

 

2.User

package com.cloud.spring.model;

/**
 * @author cloud
 * @data 2016年5月13日
 * @version 1.0
 * @description:普通的JavaBean
 */
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;
    }
}

 

3.UserDAO

package com.cloud.spring.dao;

import com.cloud.spring.model.User;

/**
 * @author cloud
 * @data 2016年5月13日
 * @version 1.0
 * @description:定义接口，定义规范，必须实现save方法
 */
public interface UserDAO {
    public void save(User user);
}

 

4.UserDAOImp

package com.cloud.spring.dao.imp;

import com.cloud.spring.dao.UserDAO;
import com.cloud.spring.model.User;

/**
 * 
 * @author cloud
 * @data 2016年5月13日
 * @version 1.0
 * @description:实现接口，重写方法
 */
public class UserDAOImpl implements UserDAO {

    private int daoId;
    
    public int getDaoId() {
        return daoId;
    }

    public void setDaoId(int daoId) {
        this.daoId = daoId;
    }

    public void save(User user) {
        System.out.println("user saved!");
    }
    
    @Override
    public String toString(){
        return "daoId="+daoId;
    }

}

 

5.UserService

package com.cloud.spring.service;

import com.cloud.spring.dao.UserDAO;
import com.cloud.spring.model.User;

/**
 * 
 * @author cloud
 * @data 2016年5月13日
 * @version 1.0
 * @description:真正的业务处理
 */
public class UserService {

    private UserDAO userDAO;

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

    public UserDAO getUserDAO() {
        return userDAO;
    }

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

 

6.TestSpring

package com.cloud.spring.test;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.cloud.spring.model.User;
import com.cloud.spring.service.UserService;

public class TestSpring {
    public static void main(String[] args) {
        try {
            ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
            UserService service = (UserService) ctx.getBean("userService");
            System.out.println(service.getUserDAO());
        } catch (BeansException e) {
            e.printStackTrace();
        }
    }
}

 

7.beans.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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
        
    <!-- UserService 中有个实例域UserDAO，需要将UserDAOImp的一个实例注入到UserDAO中去 -->
    <bean name="userDAO" class="com.cloud.spring.dao.imp.UserDAOImpl" >
        <property name="daoId" value="1"/>
    </bean>
    
    <bean name="userDAO2" class="com.cloud.spring.dao.imp.UserDAOImpl" >
        <property name="daoId" value="2"/>
    </bean>
    
    <!-- 无需指定，Spring可以帮助我们进行自动装配，可以按照name或者按照type进行自定填充 -->
    <bean id="userService" class="com.cloud.spring.service.UserService"
    scope="prototype" autowire="byName">
        
    </bean>
</beans>