Spring实战——Qualifier注解

野性酷女 2021-07-24 15:46 406阅读 0赞

**一 配置**

<?xml version="1.0" encoding="GBK"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns:context="http://www.springframework.org/schema/context"
         xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-4.0.xsd">
         <context:component-scan  base-package="org.crazyit.app.service"/>    
    </beans>

**二 接口**

Axe

package org.crazyit.app.service;
    
    public interface Axe
    {
         public String chop();
    }

Person

package org.crazyit.app.service;
    
    public interface Person
    {
         public void useAxe();
    }

**三 Bean**

Chinese

package org.crazyit.app.service.impl;
    
    
    import org.springframework.stereotype.*;
    import org.springframework.beans.factory.annotation.*;
    
    
    import org.crazyit.app.service.*;
    
    
    @Component
    public class Chinese implements Person
    {
        @Autowired
        @Qualifier("steelAxe")
        private Axe axe;
    //    // axe的setter方法
    //    @Autowired
    //    public void setAxe(@Qualifier("stoneAxe") Axe axe)
    //    {
    //        this.axe = axe;
    //    }
        // 实现Person接口的useAxe()方法
        public void useAxe()
        {
            // 调用axe的chop()方法，
            // 表明Person对象依赖于axe对象
            System.out.println(axe.chop());
        }
    }

SteelAxe

package org.crazyit.app.service.impl;
    
    
    import org.springframework.stereotype.*;
    
    
    import org.crazyit.app.service.*;
    
    @Component
    public class SteelAxe implements Axe
    {
        public String chop()
        {
            return "钢斧砍柴真快";
        }
    }

StoneAxe

package org.crazyit.app.service.impl;
    
    
    import org.springframework.stereotype.*;
    
    
    import org.crazyit.app.service.*;
    
    @Component
    public class StoneAxe implements Axe
    {
        public String chop()
        {
            return "石斧砍柴好慢";
        }
    }

**四 测试类**

package lee;
    
    
    import org.springframework.context.*;
    import org.springframework.context.support.*;
    
    import org.crazyit.app.service.*;
    
    public class BeanTest
    {
        public static void main(String[] args)
        {
            // 创建Spring容器
            AbstractApplicationContext ctx = new
                ClassPathXmlApplicationContext("beans.xml");
            // 注册关闭钩子
            ctx.registerShutdownHook();
            Person person = ctx.getBean("chinese" , Person.class);
            person.useAxe();
        }
    }

**五 测试结果**

钢斧砍柴真快