public class AccessibleObject implements AnnotatedElement {
  ...
  //取得全部Annotation
  public Annotation[] getAnnotations() {
    return getDeclaredAnnotations();
  }  
  ...
}
public final class Method extends Executable {
  ...
  public Annotation[] getDeclaredAnnotations() {
    //針對Method類，需要調用父類的getDeclaredAnnotations方法
    return super.getDeclaredAnnotations();
  }  
  ...
}
//Method的父類Executable的getDeclaredAnnotations實現全部注解信息的獲取
public abstract class Executable extends AccessibleObject
  implements Member, GenericDeclaration {
  ...
  public Annotation[] getDeclaredAnnotations() {
    return AnnotationParser.toArray(declaredAnnotations());
  }  
  ...
}

public final class Method extends Executable {
  ...
  ////取得指定Annotation
  public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
    return super.getAnnotation(annotationClass);
  }
  ...
}
public abstract class Executable extends AccessibleObject
  implements Member, GenericDeclaration {
  ...
  public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
    Objects.requireNonNull(annotationClass);
    //獲得指定注解類的信息
    return annotationClass.cast(declaredAnnotations().get(annotationClass));
  }  
  ...
}