I tried to create a class with annotation processor and Kotlin Poet. This is my code:
@AutoService(Processor::class)
class TailProcessor : AbstractProcessor() {
override fun process(elementTypeSet: MutableSet<out TypeElement>?, roundEnvironment: RoundEnvironment?): Boolean {
roundEnvironment?.getElementsAnnotatedWith(Tail::class.java)?.forEach {
if (it.javaClass.kotlin.isData) {
print("You are doing it right")
val className = it.simpleName.toString()
val pack = processingEnv.elementUtils.getPackageOf(it).toString()
val variables = ElementFilter.fieldsIn(elementTypeSet)
startClassGeneration(className, pack, variables)
} else {
return false
}
}
return false
}
override fun getSupportedSourceVersion(): SourceVersion = SourceVersion.latest()
override fun getSupportedAnnotationTypes(): MutableSet<String> = mutableSetOf(Tail::class.java.name)
private fun startClassGeneration(
className: String,
pack: String,
variables: MutableSet<VariableElement>
) {
val fileName = "Tail$className"
val stringToBePrinted = generateStringFromIncommingValues(variables)
val printFunction = FunSpec.builder("print").addCode("print($stringToBePrinted)").build()
val generatedClass = TypeSpec.objectBuilder(fileName).addFunction(printFunction).build()
val file = FileSpec.builder(pack, fileName).addType(generatedClass).build()
val kaptKotlinGeneratedDir = processingEnv.options[KOTLIN_DIRECTORY_NAME]
file.writeTo(File(kaptKotlinGeneratedDir, "$fileName.kt"))
}
private fun generateStringFromIncommingValues(variables: MutableSet<VariableElement>): Any {
val stringBuilder = StringBuilder()
variables.forEach {
if (it.constantValue == null) {
stringBuilder.append("null\n ")
} else {
stringBuilder.append("${it.constantValue}\n")
}
}
return stringBuilder.toString()
}
companion object {
const val KOTLIN_DIRECTORY_NAME = "sxhardha.tail"
}
}
The problem, directory and file not generating. I tried to rebuild, invalidate cache + restart, clean but none of them works. The build goes successful without any errors but I see no changes. Can you check what is wrong?
I actually found the issue. I wasn't checking right if that class is a data
class or not and the condition was never met.
Instead of:
it.javaClass.kotlin.isData
Should have been:
it.kotlinMetadata as KotlinClassMetadata).data.classProto.isDataClass
But it can only be achieved by using this library here.