spring注解第02课 包扫描@ComponentScan、@ComponentScans
1.配置文件形式:
<context:component-scan base-package="com.atguigu" />
spring会扫描此包下的@Service @Repository @Component @Autoware @Resource 等注解
2.注解形式
在配置文件注解类(@Configuration)上声明@ComponentScans,里面包含多个@ComponentScan,
或是只声明@ComponentScan
package com.atguigu.config; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.FilterType; import org.springframework.context.annotation.ComponentScan.Filter; import org.springframework.context.annotation.ComponentScans; import com.atguigu.bean.Person; //配置类==配置文件 @Configuration //告诉Spring这是一个配置类 @ComponentScans( value = { @ComponentScan(value="com.atguigu",includeFilters = { /* @Filter(type=FilterType.ANNOTATION,classes={Controller.class}), @Filter(type=FilterType.ASSIGNABLE_TYPE,classes={BookService.class}),*/ @Filter(type=FilterType.CUSTOM,classes={MyTypeFilter.class}) },useDefaultFilters = false) } ) //@ComponentScan value:指定要扫描的包 //excludeFilters = Filter[] :指定扫描的时候按照什么规则排除那些组件 //includeFilters = Filter[] :指定扫描的时候只需要包含哪些组件 //FilterType.ANNOTATION:按照注解 //FilterType.ASSIGNABLE_TYPE:按照给定的类型; //FilterType.ASPECTJ:使用ASPECTJ表达式 //FilterType.REGEX:使用正则指定 //FilterType.CUSTOM:使用自定义规则 public class MainConfig { //给容器中注册一个Bean;类型为返回值的类型,id默认是用方法名作为id @Bean("person") public Person person01(){ return new Person("lisi", 20); } }
3.自定义过滤器(用于注解)
package com.atguigu; import java.io.IOException; 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; public class MyTypeFilter implements TypeFilter { public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory) throws IOException { //获取当前类的注解信息 AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata(); //获取当前类的类信息 ClassMetadata classMetadata = metadataReader.getClassMetadata(); System.out.println("------------->" + classMetadata.getClassName()); //资源信息 Resource resource = metadataReader.getResource(); if(classMetadata.getClassName().contains("Controller")){ return true; } return false; } }