spring最simple注解

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如果容器中有一个以上匹配的Bean，则可以通过@Qualifier注解限定Bean的名称，看下面的例子：

定义一个Car接口：

package com.spring.service;public interface ICar {        public String getCarName();}

两个实现类BMWCar和BenzCar：

package com.spring.service.impl;import com.spring.service.ICar;public class BMWCar implements ICar{        public String getCarName(){        return "BMW car";    }}

package com.spring.service.impl;import com.spring.service.ICar;public class BenzCar implements ICar{        public String getCarName(){        return "Benz car";    }}

再写一个CarFactory，引用car（这里先不用@Qualifier注解）：

package com.spring.model;import org.springframework.beans.factory.annotation.Autowired;import com.spring.service.ICar;public class CarFactory {        @Autowired

    @Qualifier("bmwCar")    private ICar car;        public String toString(){        return car.getCarName();    }    }

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"    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-3.0.xsd    http://www.springframework.org/schema/context    http://www.springframework.org/schema/context/spring-context-3.0.xsd    ">        <context:component-scan base-package="com.spring" />        <!-- Autowired注解配合Qualifier注解 -->    <bean id="carFactory" class="com.spring.model.CarFactory" />    <bean id="bmwCar" class="com.spring.service.impl.BMWCar" />    <bean id="benz" class="com.spring.service.impl.BenzCar" />    </beans>

测试方法：

/** * Autowired注解配合Qualifier注解 */@Testpublic void test1(){    //读取配置文件    ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext2.xml");    CarFactory carFactory=(CarFactory) ctx.getBean("carFactory");    System.out.println(carFactory.toString());}

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