Making JSON string to Kotlin object not working - json

Question

I am trying to send a multipart/formdata object to the backend that contains a Freelancer object and two image files that have to be stored on the server. The saving on disc part works, but saving the JSON string as a freelancer object is not working. I tried converting the string with Jackson objectmapper but I think I am doing something wrong. When I debug the application it crashes at mapper.readValue and goes straight to the catch().
I also tried to work with kotlinx.serializer, but the import just would not work so I switched to Jackson.
The Kotlin controller that takes in the request:
private val imageDirectory = System.getProperty("user.dir") + "/images/"
#PostMapping(consumes = ["multipart/form-data"])
fun saveUser(
#RequestParam("profileImage") profileImage: MultipartFile,
#RequestParam("fileIdImage") fileIdImage: MultipartFile,
#RequestParam("freelancer") freelancer: String,
): ResponseEntity<*> {
return try {
val mapper = ObjectMapper();
val freelancerJson: Freelancer = mapper.readValue(freelancer, Freelancer::class.java)
println(freelancerJson.aboutYou)
makeDirectoryIfNotExist(imageDirectory)
val profileImagePath: Path = Paths.get(imageDirectory, profileImage.originalFilename)
val idImagePath: Path = Paths.get(imageDirectory, fileIdImage.originalFilename)
Files.write(profileImagePath, profileImage.bytes);
Files.write(idImagePath, fileIdImage.bytes);
JsonResponse(HttpStatus.OK, "Saved freelancer} ").createResponseEntity()
} catch (e: Exception) {
JsonResponse(HttpStatus.INTERNAL_SERVER_ERROR, e.message.toString()).createResponseEntity()
}
}
The request from the front end using vue:
The console output of the formdata:
Freelancer model:
#Entity
data class Freelancer(
#Id
val id: Int,
//maps ID to freelancer primary key
#MapsId
#OneToOne(targetEntity = User::class)
#JoinColumn(name = "freelancer_id")
//ignores the freelancer id because it is already mapped to val id
#JsonIgnore
val freelancerId: User,
val firstName: String? = null,
val lastName: String? = null,
val dateOfBirth: Date? = null,
val kvk: String? = null,
val btw: String? = null,
val phone: String? = null,
val street: String? = null,
val zipcode: String? = null,
val city: String? = null,
val housenumber: Int? = 0,
val addition: String? = null,
val nameCardHolder: String? = null,
val iban: String? = null,
val referral: String? = null,
val specialism: String? = null,
val aboutYou: String? = null,
val motivation: String? = null,
val workExperience: Int? = null,
val driverLicense: Boolean? = null,
val ownTransport: Boolean? = null,
val identificationImage: String? = null,
val smallBusinessScheme: Boolean? = false,
val profileImage: String? = null,
val previousWorkedPlatform: String? = null,
val servicesAmount: Int? = null,
val previousWorkedRating: Int? = null,
val foundBy: String? = null,
val privacyStatement: Boolean? = null,
)

Answer 1

I solved it by adding ID to the Json object I was sending to the backend, because my model has a one-to-one relation with another model I had to include it when mapping the Json to the model.