java - 如何将注释类型作为方法参数传递？

Question

有一种处理注释的方法，例如

public void getAnnotationValue(ProceedingJoinPoint joinPoint)
{
     MethodSignature methodSignature = (MethodSignature) joinPoint.getStaticPart().getSignature();
     Method method = methodSignature.getMethod();
     Annotation annotation = method.getParameterAnnotations()[0][0];
    RequestHeader requestParam = (RequestHeader) annotation;
    System.out.println(requestParam.value());
}

我想将其转换为接受 joinPoint 和注释类型的通用方法，例如

getAnnotationValue(joinPoint, RequestHeader);

我尝试使用:

public void getAnnotationValue(ProceedingJoinPoint joinPoint, Class<? extends Annotation> annotationType)
    {
         MethodSignature methodSignature = (MethodSignature) joinPoint.getStaticPart().getSignature();
         Method method = methodSignature.getMethod();
         Annotation annotation = method.getParameterAnnotations()[0][0];
        annotationType requestParam = (annotationType) annotation;
        System.out.println(requestParam.value());
    }

但它提示错误，指出type unresolved error？如何处理它并将注释值传递到该函数!!

Answer 1

你能做的“最好”的事情:

public void foo(Class<? extends java.lang.annotation.Annotation> annotationClass) { ...

注释没有特定的“类型”类，但您可以使用普通的 Class 对象，并简单地表达您期望注释基类的子类。