Spring - @CompentScan全解

旧城等待， 2022-10-22 02:55 214阅读 0赞

### 文章目录 ###

*  基本使用
 *   *  excludeFilters
     *  includeFilters
 *  @ComponentScan.Filter
 *   *  4种类型
     *  自定义FilterType

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbmdzaGFuZ3dlaQ_size_16_color_FFFFFF_t_70]

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# 基本使用 #

在配置类上写@CompentScan注解来进行包扫描

@Configuration
    @ComponentScan(basePackages = { "com.artisan"})
    public class MainConfig { 
    
    }

--------------------

## excludeFilters ##

@Configuration
    @ComponentScan(basePackages = { "com.artisan"},excludeFilters = { 
            @ComponentScan.Filter(type = FilterType.ANNOTATION,value = { Controller.class}),
            @ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE,value = { ArtisanService.class})
    })
    public class MainConfig { 
    }

这里会 排除标注了@Controller注解 和 特定的ArtisanService ,不会被加载到IOC容器中。

![在这里插入图片描述][20210403105845256.gif_pic_center]

--------------------

## includeFilters ##

若使用包含的用法， 需要把**useDefaultFilters**属性设置为**false**（true表示扫描全部的）

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

![在这里插入图片描述][20210403105857501.gif_pic_center]

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# @ComponentScan.Filter #

## 4种类型 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbmdzaGFuZ3dlaQ_size_16_color_FFFFFF_t_70 1]

*  注解形式的FilterType.**ANNOTATION** `比如@Controller @Service @Repository @Compent`
 *  **指定类型**的 FilterType.**ASSIGNABLE\_TYPE**
    
        @ComponentScan.Filter(type =
        FilterType.ASSIGNABLE_TYPE,value = { ArtisanService.class})
 *  aspectj类型的 FilterType.ASPECTJ(不常用)
 *  正则表达式的 FilterType.REGEX(不常用)
 *  自定义的 FilterType.**CUSTOM**

--------------------

## 自定义FilterType ##

import org.springframework.core.io.Resource;
    import org.springframework.core.type.AnnotationMetadata;
    import org.springframework.core.type.ClassMetadata;
    import org.springframework.core.type.classreading.MetadataReader;
    import org.springframework.core.type.classreading.MetadataReaderFactory;
    import org.springframework.core.type.filter.TypeFilter;
    
    import java.io.IOException;
    
     
    public class ArtisanFilterType implements TypeFilter { 
    
        @Override
        public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory) throws IOException { 
            //获取当前类的注解源信息
            AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata();
    
            //获取当前类的class的源信息
            ClassMetadata classMetadata = metadataReader.getClassMetadata();
            //获取当前类的资源信息
            Resource resource =  metadataReader.getResource();
            System.out.println("类的路径:"+classMetadata.getClassName());
            if(classMetadata.getClassName().contains("dao")) { 
                return true;
            }
            return false;
        }
    }

引用自定义类型的Filter

@ComponentScan(basePackages = { "com.tuling.testcompentscan"},excludeFilters = {  
            @ComponentScan.Filter(type = FilterType.CUSTOM,value = ArtisanFilterType.class)
    },includeFilters = { 
            @ComponentScan.Filter(type = FilterType.ANNOTATION,value = Repository.class)
    })

--------------------

测试的话，打印下beanDefinition 即可

public class MainClass { 
    
        public static void main(String[] args) { 
            AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(MainConfig.class);
            String[] beanDefinationNames = ctx.getBeanDefinitionNames();
            for (String name:beanDefinationNames) { 
                System.out.println("bean的定义信息:"+name);
            }
    
        }
    }

![在这里插入图片描述][20210403110601621.gif_pic_center]

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[20210403105845256.gif_pic_center]: /images/20221022/94ab2aaf03824a1fa5f87ee0b442d0db.png
[20210403105857501.gif_pic_center]: /images/20221022/0b09178b68c041b790becc577d4acb39.png
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[20210403110601621.gif_pic_center]: /images/20221022/ae50647243464021b6d1125ec3c3a8e5.png