Spring注解系列二：组件注册-@ComponentScan

转:https://www.jianshu.com/p/170cf6c36dce

1、在配置类中配置包扫描

<!-- 包扫描、只要标注了@Controller、@Service、@Repository，@Component -->
<context:component-scan base-package="com.atguigu"></context:component-scan>

@Configuration  
@ComponentScan(value="com.atguigu")
public class MainConfig {
}

2、创建组件

@Controller
public class BookController {
}

@Service
public class BookService {
}

@Repository
public class BookDao {
}

3、创建测试方法

@SuppressWarnings("resource")
@Test
public void test01(){
    AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfig.class);
    String[] definitionNames = applicationContext.getBeanDefinitionNames();
    for (String name : definitionNames) {
        System.out.println(name);
    }
}

图片.png

4、包扫描时排除某些组件excludeFilters

@Configuration  
@ComponentScan(value="com.atguigu",excludeFilters = {
        @Filter(type=FilterType.ANNOTATION,classes={Controller.class})
})
public class MainConfig {
}

图片.png

5、包扫描时只包含某些组件includeFilters

//以前要只包含某些组件必须使用use-default-filters="false"禁用默认规则。默认是扫描所有的
<context:component-scan base-package="com.atguigu" use-default-filters="false"></context:component-scan> 

@Configuration  
@ComponentScan(value="com.atguigu",includeFilters = {
        @Filter(type=FilterType.ANNOTATION,classes={Controller.class})
},useDefaultFilters = false)
public class MainConfig {
}

图片.png

6、@ComponentScans注解

@Configuration 
@ComponentScans(value = @ComponentScan(value="com.atguigu",includeFilters = {
        @Filter(type=FilterType.ANNOTATION,classes={Controller.class})
},useDefaultFilters = false))
public class MainConfig {
}

图片.png

7、@ComponentScan可以重复标注

@ComponentScan(value="com.atguigu",excludeFilters = {
        @Filter(type=FilterType.ANNOTATION,classes={Service.class})
},useDefaultFilters = false)
@ComponentScan(value="com.atguigu",includeFilters = {
        @Filter(type=FilterType.ANNOTATION,classes={Controller.class})
},useDefaultFilters = false)
public class MainConfig {
}