Set注入

一：Dao层  

package com.spring.chapter3.dao;

public interface FruitDao {
	public void create();
}

    实现类： 

package com.spring.chapter3.dao.impl;

import com.spring.chapter3.dao.FruitDao;

public class FruitDaoImpl implements FruitDao {
	public void create() {
		System.out.println("Dao层方法create被调用");
	}
}

    服务层接口： 

package com.spring.chapter3.service;

public interface FruitService {
	public void create();
}

     服务层实现类：  

package com.spring.chapter3.service.impl;

import com.spring.chapter3.dao.FruitDao;
import com.spring.chapter3.service.FruitService;

public class FruitServiceImpl implements FruitService {
	private FruitDao fruitDao;
	public void create() {
		fruitDao.create();
	}
	public void setFruitDao(FruitDao fruitDao) {
		this.fruitDao = fruitDao;
	}	
}

     测试类：  

package com.spring.chapter3.service.impl;

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

import com.spring.chapter3.service.FruitService;

public class Test {
	public static void main(String[] args) {
		ApplicationContext act = new ClassPathXmlApplicationContext("chapter3.xml");
		FruitService fruitService = (FruitService) act.getBean("fruitService");
		fruitService.create();
	}
}

     xml配置(chapter3.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-2.5.xsd">
	<bean id="fruitDao" class="com.spring.chapter3.dao.impl.FruitDaoImpl"/>
	<bean id="fruitService" class="com.spring.chapter3.service.impl.FruitServiceImpl">
		<property name="fruitDao" ref="fruitDao" />
	</bean>
</beans>

     注意：

     <property name="fruitDao" ref="fruitDao" />

     这里的name="fruitDao"并不是私有属性的名字,实际上Spring会根据这个名字找对应的setFruitDao这个方法来达到注入的一个目的.