How to use JsonNames to parse multiple names for JSON field in Kotlinx Serialization?

Question

How to use JsonNames to parse multiple names for JSON field in Kotlinx Serialization. For normal data class it works fine

@OptIn(ExperimentalSerializationApi::class)
@Serializable
data class Project(@JsonNames("title") val name: String)

fun main() {
  val project = Json.decodeFromString<Project>("""{"name":"kotlinx.serialization"}""")
  println(project)
  val oldProject = Json.decodeFromString<Project>("""{"title":"kotlinx.coroutines"}""")
  println(oldProject)
}

Project(name=kotlinx.serialization)
Project(name=kotlinx.coroutines)

But for Type generic data class like GoogleBaseApiResponse where T is of any data class

@OptIn(ExperimentalSerializationApi::class)
@Serializable
data class GoogleBaseApiResponse<T> (
    var status : String = "",
    var error_message : String? = null,
    @JsonNames("results", "predictions", "result") var responseData : T? = null
)

Where T is Something like data class or arraylist of data class

Following Errors occurs

Exception in thread "main" java.lang.IllegalStateException: Problem with constructing exception message
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializerClassLowering.lower(SerializationLoweringExtension.kt:184)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:46)
    at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitClass(IrElementVisitorVoid.kt:111)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:64)
    at org.jetbrains.kotlin.ir.declarations.IrClass.acceptChildren(IrClass.kt:68)
    at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptChildrenVoid(IrVisitors.kt:15)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:47)
    at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitClass(IrElementVisitorVoid.kt:111)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitClass(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlin.ir.declarations.IrClass.accept(IrClass.kt:64)
    at org.jetbrains.kotlin.ir.declarations.IrFile.acceptChildren(IrFile.kt:36)
    at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptChildrenVoid(IrVisitors.kt:15)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitElement(SerializationLoweringExtension.kt:42)
    at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitPackageFragment(IrElementVisitorVoid.kt:190)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitPackageFragment(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitFile(IrElementVisitorVoid.kt:200)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid$DefaultImpls.visitFile(IrElementVisitorVoid.kt:198)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt$runOnFileInOrder$1.visitFile(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlin.ir.declarations.IrFile.accept(IrFile.kt:30)
    at org.jetbrains.kotlin.ir.visitors.IrVisitorsKt.acceptVoid(IrVisitors.kt:11)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtensionKt.runOnFileInOrder(SerializationLoweringExtension.kt:40)
    at org.jetbrains.kotlinx.serialization.compiler.extensions.SerializationLoweringExtension.generate(SerializationLoweringExtension.kt:149)
    at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.convertToIr$lambda$1(JvmIrCodegenFactory.kt:186)
    at org.jetbrains.kotlin.psi2ir.Psi2IrTranslator.generateModuleFragment(Psi2IrTranslator.kt:104)
    at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.convertToIr(JvmIrCodegenFactory.kt:218)
    at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.convertToIr(JvmIrCodegenFactory.kt:55)
    at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.convertToIr(KotlinToJVMBytecodeCompiler.kt:225)
    at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:102)
    at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli$default(KotlinToJVMBytecodeCompiler.kt:47)
    at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:167)
    at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:53)
    at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:101)
    at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:47)
    at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:101)
    at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:79)
    at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:43)
    at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMainNoExit(CLITool.kt:179)
    at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMainNoExit$default(CLITool.kt:177)
    at org.jetbrains.kotlin.cli.common.CLITool$Companion.doMain(CLITool.kt:166)
    at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler$Companion.main(K2JVMCompiler.kt:250)
    at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.main(K2JVMCompiler.kt)

Whether is possible to use @JsonNames annotations in Type generic data class?.

Sample Code is below

val httpResponse = httpClient.post {
                    url(PLACES_DETAILS)
                    formData {
                        parameter(PLACE_ID_KEY, userAppLocation.userCityId)
                        parameter(API_KEY, appSettings.getAppConfigModel()?.getMapApiKey())
                    }
                }.call.response
                httpResponse.body<GoogleBaseApiResponse<AddressFromLatLngModel>>().also { apiResponse ->
                    if (apiResponse.status.lowercase() == Constants.OKAY_STATUS.lowercase()) {
                        Napier.d(tag = tag, message = apiResponse.printJSONValue())
                        val newUserAppLocation = userAppLocation.copy(
                            userLat = apiResponse. responseData?.geometry?.location?.lat?:0.0,
                            userLng = apiResponse. responseData?.geometry?.location?.lng?:0.0
                        )
                        emit(NetworkResult.Success(newUserAppLocation))
                    } else {
                        emit(NetworkResult.Error(apiResponse.error_message))
                    }
                }



Where,
GoogleBaseApiResponse --> 
@OptIn(ExperimentalSerializationApi::class)
@Serializable
data class GoogleBaseApiResponse<T> (
    var status : String = "",
    var error_message : String? = null,
    @JsonNames("results", "predictions", "result") var responseData : T? = null
)


AddressFromLatLngModel -->
@Serializable
data class AddressFromLatLngModel(
    var formatted_address : String = "",
    var geometry : GeometryModel = GeometryModel(),
    var address_components : ArrayList<AddressComponentsModel> = arrayListOf()
)

GeometryModel is --> 
@Serializable
data class GeometryModel(
    var location : LocationModel = LocationModel()
)

LocationModel is -->
@Serializable
data class LocationModel(
    var lat : Double = 0.0,
    var lng : Double = 0.0
)

AddressComponentsModel -->
@Serializable
data class AddressComponentsModel(
    var long_name : String = "",
    var short_name : String = ""
)

When are you getting that error? Your code works just fine for me. — Jorn, Aug 14 '23 at 12:17
The classes you added have neither `JsonNames` nor any generic types on the class (only on the fields), nor any new info on the extension. In other words, you haven't added anything I can use to help you further. — Jorn, Aug 14 '23 at 13:57

Jorn · Answer 1 · 2023-08-14T12:49:44.117

0

The code you posted works just fine for me:

    val json = Json.encodeToString(GoogleBaseApiResponse("st", "err", 42))
        .replace("responseData", "predictions") // simulate "alternate" name
    println(json) // {"status":"st","error_message":"err","predictions":42}
    val x = Json.decodeFromString<GoogleBaseApiResponse<Int>>(json)
    println(x) // GoogleBaseApiResponse(status=st, error_message=err, responseData=42)

But since your error happens in the SerializationLoweringExtension, I'd look into configuration regarding that extension, and code that makes use of it. If you post more relevant details, we might be able to help you further.

edited Aug 14 '23 at 12:49

answered Aug 14 '23 at 12:17

Jorn

20,612
18
79
126

I am using @JsonNames("results", "predictions", "result") annotation in GoogleBaseApiResponse. Without @JsonNames everything works. My scenario is to use **@JsonNames** because key **results** is for fetching address list from google, **predictions** is for fetching address by search query and **result** is for getting address data based on Latitude and Longitude – Suman Radhakrishnan Aug 14 '23 at 12:45
@SumanRadhakrishnan Still works with the alternate name, see updated answer. Like I said, your problem is not related to `@JsonNames` or the generic parameter. – Jorn Aug 14 '23 at 12:50
Then why SerializationLoweringExtension error happend to me? – Suman Radhakrishnan Aug 14 '23 at 12:52
There's a problem relating to that extension in code you haven't posted, so we can't know that. – Jorn Aug 14 '23 at 12:53
But its works fine without @JsonNames. So I think their is no problem in extension – Suman Radhakrishnan Aug 14 '23 at 13:05
@SumanRadhakrishnan Then how do you explain that my example works fine? – Jorn Aug 14 '23 at 13:06
In my case T is Not a Integer or String. Its Something like Data class or ArrayList of Data Class – Suman Radhakrishnan Aug 14 '23 at 13:07
@SumanRadhakrishnan That sounds like relevant information that should be in the question, along with the actual JSON you are parsing. – Jorn Aug 14 '23 at 13:08
How do i post my sample code in comment section? – Suman Radhakrishnan Aug 14 '23 at 13:10
You don't. Edit your question instead. – Jorn Aug 14 '23 at 13:11
I updated my questing. Please check whether it okay or not? – Suman Radhakrishnan Aug 14 '23 at 13:16

score -1 · Answer 2 · answered Aug 14 '23 at 13:14

-1

if i got it you need to user same parameter to different json keys you need to use alternate attribute

so your data class will be like

@Serializable

data class Project(@SerializedName("title",alternate =["name"]) val name: String)

answered Aug 14 '23 at 13:14

Noah Mohamed

114
1
1
8

How to use JsonNames to parse multiple names for JSON field in Kotlinx Serialization?

2 Answers2