Question

I’m using annotations for generating documentation for an API that I’m publishing. I have it defined like this:

@Documented
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface PropertyInfo {

    String description();

    String since() default "5.8";

    String link() default "";
}

Now this works fine when I process the classes using reflection. I can get the list of annotations on the method. The issue I have is that it only works if I instantiate a new instance of the object I’m processing. I would prefer not to have to instantiate them to get the annotation. I tried RetentionPolicy.CLASS but it doesn’t work.

Any ideas?

Answer 1

You don’t need to instantiate an object, you just need the class. Here is an example:

public class Snippet {

  @PropertyInfo(description = "test")
  public void testMethod() {
  }
  public static void main(String[] args)  {
    for (Method m : Snippet.class.getMethods()) {
      if (m.isAnnotationPresent(PropertyInfo.class)) {
        System.out.println("The method "+m.getName()+
        " has an annotation " + m.getAnnotation(PropertyInfo.class).description());
      }
    }
  }
}