Hey team! im working on a HTTP API and adding pers...

# ktor

[Eduardo Ruesta]

Hey team! im working on a HTTP API and adding persistence using db: i merged the two sample project we have in the Ktor documentation: the customer api and this one https://ktor.io/docs/db-persistence.html... this is mas post routing:

post {
    val formParameters = call.receiveParameters()
    val firstName = formParameters.getOrFail("firstName")
    val lastName = formParameters.getOrFail("lastName")
    val email = formParameters.getOrFail("email")
    val customer = dao.addNewCustomer(firstName, lastName, email)
    call.respond(mapOf("customer" to customer))
}

where customer is the route (/customer) : Im trying to add a new customer using curl command: curl -H "Content-Type: application/json" -d '{"firstName": "Raul", "lastName": "Garcia", "email": "<mailto:[e-mail]|[e-mail]>"}' <http://127.0.0.1:8080/customer>
and im having the issue

2024-04-22 162936.461 [eventLoopGroupProxy-4-3] DEBUG Application - Unhandled: POST - /customer. Exception class io.ktor.server.plugins.BadRequestException: Failed to convert request body to class io.ktor.http.Parameters

Caused by: io.ktor.serialization.JsonConvertException: Illegal input: Polymorphic serializer was not found for missing class discriminator ('null')

JSON input: {"firstName":"Raul","lastName":"Garcia","email":"[e-mail]"}

[Eduardo Ruesta]

Im new on this backend stuff! any idea which coulb be the issue? and how can i add a new customer? the only way i found was doing an INSERT in the database

[Chrimaeon]

You should look up the difference between „form parameters“ that you backend expects and a „json body“ that you actually send in the curl command via -d

[Chrimaeon]

https://ktor.io/docs/server-requests.html#objects

[Chrimaeon]

https://ktor.io/docs/server-requests.html#form_parameters

[Eduardo Ruesta]

Thanks @Chrimaeon, really helpful