Spring注解系列二：组件注册-@ComponentScan

谁践踏了优雅 2022-02-04 03:51 277阅读 0赞

1、在配置类中配置包扫描

<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);
    	}
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpemhpcWlhbmcxMjE3_size_16_color_FFFFFF_t_70]  
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 {
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpemhpcWlhbmcxMjE3_size_16_color_FFFFFF_t_70 1]  
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 {
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpemhpcWlhbmcxMjE3_size_16_color_FFFFFF_t_70 2]  
6、@ComponentScans注解

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

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpemhpcWlhbmcxMjE3_size_16_color_FFFFFF_t_70 2]  
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 {
    }

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