Why is Spring's @Component Annotation RUNTIME?-CodePudding

I am wondering, why Spring's implementation of the @Component Annotation has RetentionPolicy.RUNTIME. Here's the official implementation from github

@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Indexed
public @interface Component {
    String value() default "";
}

In my thought, the scanning for all Spring-Components annotated with @Component would be done at compile-time and all the results (annotated classes) would somehow be stored inside the ApplicationContext. I guess I am wrong, but why does this annotation need to be RetentionPolicy.Runtime?

CodePudding user response：

The component scanning is done at the startup, not at the compilation. Also, the aspects (AOP) are created at the runtime