Create collection of JSONObjects from list of Kotlin objects - json

Question

I have a room database from which I can get a List<LearningEvent>, which I then have to convert into a Collection<JSONObject> and return it. How can I efficiently do that?
Here's the LearningEvent class:
#Entity(tableName = "learningEvents")
data class LearningEvent(
#ColumnInfo(name = "learningeventid")
#PrimaryKey(autoGenerate = true)
var id: Int? = null,
var sessionId: Long,
var time: Float,
var eventType: String,
var description: String,
var feedback: String
)
Here's the DAO:
#Query("SELECT * FROM learningEvents WHERE sessionId = :sessionId")
suspend fun getAllLearningEvents(sessionId: Long?): List<LearningEvent>
And here's my non-working/non-building code for the getEvents() function:
override suspend fun getEvents(): Collection<JSONObject> =
withContext(Dispatchers.IO) {
Log.d("\ngetEvents(eventType)", currentSessionId.toString())
if (currentSessionId === null) {
throw Exception("Current session Id is null; Session cannot be retrieved.")
}
var gson = Gson();
// Return JSON object collection of table rows.
var learningEvents = db.learningEventDao().getAllLearningEvents(currentSessionId);
var returnCollection = emptyList<JSONObject>();
learningEvents.forEach{element ->
var singleObject = gson.toJsonTree(element);
returnCollection += singleObject;
}
return#withContext returnCollection;
}

Answer 1

In my humble opinion, you can convert LearningEvent to JSONObject using .toJson. Here the sample code:
var learningEvents = db.learningEventDao().getAllLearningEvents(currentSessionId);
var returnCollection = emptyList<JSONObject>();
learningEvents.forEach{ element ->
val singleObject = gson.toJson(element);
returnCollection += JSONObject(singleObject);
}