Update KotlinSerializer.kt

Add handling of null, Void and Object

examples/features/src/main/java/com/github/kagkarlsson/examples/kotlin/KotlinSerializer.kt

@@ -10,11 +10,23 @@ class KotlinSerializer : Serializer {
     val CHARSET = StandardCharsets.UTF_8
 
     override fun serialize(data: Any): ByteArray {
+        if (data == null) {
+            return ByteArray(0)
+        }
         val serializer = serializer(data.javaClass)
         return Json.encodeToString(serializer, data).toByteArray(CHARSET);
     }
 
     override fun <T : Any?> deserialize(clazz: Class<T>, serializedData: ByteArray): T {
+        if (serializedData == null || clazz == Void::class.java) {
+            return null
+        }
+
+        // If we do not know the class (e.g. java.lang.Object), decode as generic JSON
+        if (clazz == Any::class.java) {
+            return Json.decodeFromString(JsonElement.serializer(), serializedData.decodeToString()) as T
+        }
+
         // Hackish workaround?
         // https://github.com/Kotlin/kotlinx.serialization/issues/1134
         // https://stackoverflow.com/questions/64284767/replace-jackson-with-kotlinx-serialization-in-javalin-framework/64285478#64285478