Spring 自动化装配Bean

public interface CompactDisc {
    public abstract void play();
}

@Component("SgtPeppers")
public class SgtPeppers implements CompactDisc {
    private String title = "Sgt.Pepper‘s Lonely Hearts Club Band";
    private String artist = "The Beatles";

    @Override
    public void play() {
        System.out.println("playing" + title + " by " + artist);
    }
}

@Component("CDplayer")//表明该类作为组件类，没必要显示的配置Bean实例,括号内为组件名
public class CDPlayer {
    /*
    * @Autowired注解可以用在构造器上，也可以用在set方法上，也能直接放在下列代码所示地方
    * spring会满足有该注解的依赖，如果只有一个bean匹配依赖需求的话，这个bean就会被装配进来
      @Autowired 默认按类型装配
    * */
    @Autowired
    private CompactDisc cd;

    public CompactDisc getCd() {
        return cd;
    }

    public void setCd(CompactDisc cd) {
        this.cd = cd;
    }
    public void play(){
        cd.play();
    }
}

public class CDPlayerTest {
    public static void main(String[] args) {
        ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
        CDPlayer cdPlayer= (CDPlayer) context.getBean("CDplayer");
        cdPlayer.play();
    }
}

 <context:component-scan base-package="com.xue.soundsystem"></context:component-scan>