python学习之----初见网络爬虫（输出整个网页html的代码）

被@Component注解标注的注解有：@Service, @Repository, @Controller, @Configuration

@Target(ElementType.TYPE)

@Retention(RetentionPolicy.RUNTIME)

@Documented

@Indexed

public @interface Component {

    /**

     * The value may indicate a suggestion for a logical component name,

     * to be turned into a Spring bean in case of an autodetected component.

     * @return the suggested component name, if any (or empty String otherwise)

     */

    String value() default "";

}

@Target(ElementType.TYPE)

@Retention(RetentionPolicy.RUNTIME)

@Documented

@Component

public @interface Configuration {

    @AliasFor(annotation = Component.class)

    String value() default "";

}

@ComponentScan会扫描带有@Component注解的类
处理类：
ConfigurationClassParser
扫描类：

ClassPathBeanDefinitionScanner extends ClassPathScanningCandidateComponentProvider 

protected void registerDefaultFilters() {

   this.includeFilters.add(new AnnotationTypeFilter(Component.class));

@ComponentScan:

@Retention(RetentionPolicy.RUNTIME)

@Target(ElementType.TYPE)

@Documented

@Repeatable(ComponentScans.class) @since 1.8

public @interface ComponentScan {

一般的注解只能写一次，而被@Repeatable标注的注解可以写多次

@ComponentScan(basePackages = "com")
@ComponentScan(basePackages = "com.example")
public class Demo