Retrieve annotation enum property leads to java.lang.ClassCastException

[Clement-Jean]

Having the following enum:

enum class Priority {
   MIN,
   MEDIUM,
   MAX
}

and the following annotation:

@Retention(AnnotationRetention.SOURCE)
@Target(AnnotationTarget.CLASS)
annotation class FFProvider(val priority: Priority = Priority.MIN)

I'm trying to retrieve the value of that priority property with the following code:

private fun KSClassDeclaration.getPriority() = annotations.first {
   it.shortName.getShortName() == "FFProvider"
}.arguments.first {
   it.name?.getShortName() == "priority"
}.value as Priority

However, I get a java.lang.ClassCastException saying:

java.lang.ClassCastException: class com.google.devtools.ksp.symbol.impl.kotlin.KSTypeImpl cannot be cast to class XXX$Priority (com.google.devtools.ksp.symbol.impl.kotlin.KSTypeImpl is in unnamed module of loader java.net.URLClassLoader @5be45b81; XXX$Priority is in unnamed module of loader java.net.URLClassLoader @50071d6d)

Am I doing something wrong or is it a bug? No idea. If its the former please explain the problem to me (and potentially make the error more explicit).

Ps: works with Int type

[Clement-Jean]

Another question is how would you get the default value of the parameter in the Annotation class ?

[mars885]

All my default values of the annotation class are set to null for some reason. In the quickstart guide, it says that KSP's analog of Java's Element.getAnnotation is not yet implemented. Has this already been implemented or am I missing something?

[mars885]

@ting-yuan @neetopia Any thoughts on this?

[neetopia]

If the annotation class is declared in source code, or from a binary library that is compiled from Java source code, then default value should work. The remaining scenario where it is from a kotlin library is not working as a known issue we are tracking.

[mars885]

If the annotation class is declared in source code, or from a binary library that is compiled from Java source code, then default value should work. The remaining scenario where it is from a kotlin library is not working as a known issue we are tracking.

Does that also apply to fetching arguments from the annotation?

For example:

annotation class BindType(
  val to: KClass<*> = Nothing::class,
  val installIn: Component = Component.NONE
) {

    enum class Component {

      NONE,

      SINGLETON,
      ACTIVITY_RETAINED,
      SERVICE,
      ACTIVITY,
      VIEW_MODEL,
      FRAGMENT,
      VIEW,
      VIEW_WITH_FRAGMENT,

      CUSTOM

    }

}

// then

@BindType(
  to = Testable::class,
  installIn = BindType.Component.VIEW
)
class Test : Testable

// then

fun getComponent(bindAnnotation: KSAnnotation): BindType.Component {
  return bindAnnotation.arguments
      .associate { it.name!!.asString() to it.value }
      .getValue("installIn") // returns KSTypeImpl, instead of BindType.Component
}

In javac, it is as simple as this:

fun getComponent(element: Element): BindType.Component {
  return element.getAnnotation(BindType::class.java).installIn
}

What is the equivalent of the above code in KSP? Thanks in advance.

[ting-yuan]

In Java's analogy, what's provided in KSP is closer to getAnnotationMirrors but not getAnnotation, because the annotation type may not be instantiable at compile time. We plan to implement getAnnotation in utils using reflection (e.g., java.lang.reflect.Proxy) but haven't have time to do so yet.

Ref: https://docs.oracle.com/javase/8/docs/api/javax/lang/model/element/Element.html

[Alankar0416]

Just checking did we manage to fix this. I want to get the enum value passed to one of the annotations. Similar to @mars885 it's returning KSTypeImpl

[jithu-10]

Is there any solution avail now?. I have same type of problem, @Target(AnnotationTarget.CLASS) @Retention(AnnotationRetention.SOURCE) annotation class GenerateDI( val moduleType: ModuleType, val superType: KClass<*> = Unit::class, )

@GenerateDI(ModuleType.ACTIVITY, BaseClass::class) class SampleClass : BaseClass

generateDIAnnotation?.arguments?.get(0)?.value.toString()

I used this line of code to get the param value as string. But is there any other way to type cast value?