How to change the field name of `Pair`? The code ...

# android

[Aldan Rizki Santosa]

How to change the field name of Pair?

The code like this :

val distributorNotes = ArrayList<PairDistributorNotes<String, String>>()

distributorNotes.add(PairDistributorNotes("350631771", "test"))

data class PairDistributorNotes<out x, out y>(val distributor_id: x, val note: y) {
    override fun toString(): String = "($distributor_id, $note)"
}

and i create asReverse() with distinctBy

val dataJson = Gson().toJson(distributorNotes.asReversed().distinctBy { it.distributor_id })

Output from dataJson :
[{"a":"350631771","b":"test"}]

Can field a and b change to distributor_id and note ?

Expected :
[{"distributor_id":"350631771","note":"test"}]

UPDATE

Based on Christian Grach answer, because Proguard is enabled, Gson require annotations to preserve the field name.. We need to add @field:SerializedName() on data class

data class PairDistributorNotes<out A, out B>(
      @field:SerializedName("distributor_id")
      val distributor_id: A,

      @field:SerializedName("note")
      val note: B
) {
      override fun toString(): String = "($distributor_id, $note)"
}

[Chrimaeon]

Do you have Proguard or R8 enabled? I guess Gson has some annotations to preserve the field name.

[Aldan Rizki Santosa]

Yes i have Proguard enabled, how to prevent that for Gson?

[Chrimaeon]

Like I said, there should be annotations that you apply on the properties.

[Chrimaeon]

google

[Aldan Rizki Santosa]

Ah, I see.. My bad.. it's working with it @field:SerializedName() thanks!