How to make post with data class - kotlin

Question

I have this endpoint with this structure:
uri = http://127.0.0.1:9090/tables/mask
and this payload:
{
"_id" : "5d66c9b6d5ccf30bd5b6b541",
"connectionId" : "1967c072-b5cf-4e9e-1c92-c2b49eb771c4",
"name" : "Customer",
"columns" : [
{
"name" : "FirstName",
"mask" : true
},
{
"name" : "LastName",
"mask" : false
},
{
"name" : "City",
"mask" : false
},
{
"name" : "Phone",
"mask" : false
}
],
"parentId" : null
}
in my Kotlin code I have this structure to deserialize:
data class ColumnsMaskModel (val name:String, val mask:Boolean )
data class TablesMaskModel (val _id:String, val name:String, val connectionId:String, val columns:MutableList<ColumnsMaskModel?> )
and how can I use TablesMaskModel to make a HTTP post in Kotlin

Answer 1

You'll need an HTTP client to do that. Data classes themselves has nothing to do with HTTP, they are just data structures. There are a lot of HTTP clients available on Kotlin for JVM:
java.net.HttpURLConnection
Java 9's HttpClient
Apache HttpComponents
OkHttp
Ktor
Let's see how to make HTTP requests in Ktor:
data class ColumnsMaskModel(val name: String, val mask: Boolean)
data class TablesMaskModel(val _id: String, val name: String, val connectionId: String, val columns: MutableList<ColumnsMaskModel?>)
fun main() = runBlocking {
val client = HttpClient {
install(JsonFeature) {
serializer = JacksonSerializer()
}
}
val result = client.post<String> {
url("http://httpbin.org/post")
contentType(ContentType.Application.Json)
body = TablesMaskModel(
_id = "5d66c9b6d5ccf30bd5b6b541",
connectionId = "1967c072-b5cf-4e9e-1c92-c2b49eb771c4",
name = "Customer",
columns = mutableListOf(
ColumnsMaskModel(name = "FirstName", mask = true),
ColumnsMaskModel(name = "LastName", mask = false),
ColumnsMaskModel(name = "City", mask = false),
ColumnsMaskModel(name = "Phone", mask = false)
)
)
}
println(result)
client.close()
}
Note that Ktor uses suspending functions for HTTP requests, so you'll need a coroutine scope, runBlocking in this example.
Ktor supports various "backends" for HTTP clients – Apache, Coroutines IO, curl. It also has different "features" to enable on-the-flight payloads serializations and de-serializations, like in the example above.