1 spring如何通过组件扫描和自动装配实现自动化的配置

1 首先将spring依赖的包全部导入

2 建立测试接口

public interface CompactDisc {

    void play();
}

3 具体的类实现接口

import org.springframework.stereotype.Component;

import morningstar.spring.CompactDisc;

/*
 * @Component 注解用在类上表明该类会作为组件类使用，并且告知spring要为这个类创建bean*/
@Component
public class Stgpepers implements CompactDisc {

    private String title="sgt.peper's lnnely hearts club band";
    private String artist="the beatles";
    @Override
    public void play() {
        // TODO Auto-generated method stub
        System.out.println("playing "+title+" by "+artist);
    }

}

4 创建配置类

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

import morningstar.spring.entity.Stgpepers;

@Configuration
@ComponentScan(basePackages = {"morningstar.spring.entity"})
public class CDPlayerConfig {

    /*
     *@Configuration:
     *@ComponentScan:在spring中启用组件扫描 */
}

5 建立测试：

//SpringJUnit4ClassRunner：测试开始的时候就创建spring的应用上下文
@RunWith(SpringJUnit4ClassRunner.class)
//@ContextConfiguration注解告诉spring在CDPlayerConfig类中加载配置类
@ContextConfiguration(classes =CDPlayerConfig.class )
public class CDPlayerTest {

    @Autowired
    private CompactDisc disc;

    @Rule
    public final StandardErrorStreamLog log=new StandardErrorStreamLog();
    @Autowired
    private MediaPlayer player;

    @Test
    public void cdShouldNotBeNull()
    {
        assertNotNull(disc);
        System.out.println("success");
    }

    @Test
    public void player()
    {
        player.play();
    }
}

6 结果：

测试通过