xml 注解  javaConfig

xml配置缺点 类型不安全

通过注解进行自动化装配

@Component
public class MyBeanImpl implements MyBean{
    ......
}

@Component
public class MyServiceImpl implements MyService{

    @Autowired
    private MyBean myBean;
    ......
}

@Configuration
@ComponentScan(basePackageClasses={MyBean.class,MyBean2.class})
public class MyConfig {

}

basePackageClasses 类型安全 ，值为class数组 ， 扫描这些class所在的包。

单元测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes=MyConfig.class)
public class MyServiceTest {
	
	@Autowired
	private MyService myService;
	
	@Test
	public void testMyService() {
	    ...
	}
}

注解配置的缺点 
不能修改第三方组件代码 增加注解


Java Config

@Configuration
public class MyJavaConfig {

    @Bean
    public MyBean getMyBean() {
        return new MyBeanImpl();
    }

    @Bean
    public MyService getMyService(MyBean myBean)     {
        return new MyServiceImpl(myBean);
    }
}

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = MyJavaConfig.class)
public class MyJavaConfigTest {

    @Autowired
    private MyService myService;

    @Test
    public void testMyService() {
        ...
    }
}