Spring实战之Qualifier注解用法示例

<?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>

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

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

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());
  }
}

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";
  }
}

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";
  }
}

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();
  }
}