Retrofit kotlin request code fails, why?

Question

Android

A simple request to get data in json format. The problem is that when the request is successfully (!) sent, the onResponce code is not executed at all - no result, no error, no exceptions - nothing, as if the program simply skips these lines. At the same time, onFailure() in the case of a knowingly broken request (for example, a knowingly broken link) is executed! Checked it many times. I suspect that the problem is in the data from the server - the server does not return pure json, but json inside the , . Could this be a problem?

Interface:

import retrofit2.Call
import retrofit2.http.GET

interface OrgList {
    @GET("test.php/")
    fun getcompanyes(): Call<List<Company?>?>

}

Client code:

import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory

object RetrofitClient {


   var retrofit = Retrofit.Builder()
//Адрес источника публиковать не могу, поэтому заменил
        .baseUrl("https://domain.ru/text/")
        .addConverterFactory(GsonConverterFactory.create())
        .build()
    var companyes = retrofit.create(OrgList::class.java)

    }

Actually, the request itself:

val headtext: TextView = findViewById(R.id.textView)


        try {

            val orgs: Call<List<Company?>?>? =
            RetrofitClient.companyes.getcompanyes()

            orgs?.enqueue(object : Callback<List<Company?>?> {
                override fun onFailure(call: Call<List<Company?>?>, t: Throwable) {
//Без проблем выполняется, если ссылка baseUrl битая (например, http вместо https)
                    Toast.makeText(applicationContext, "Failed callback! ${t.message}", Toast.LENGTH_LONG).show()
                }

                override fun onResponse(
                    @NonNull call: Call<List<Company?>?>,
                    @NonNull response: Response<List<Company?>?>
                ) {
/*Ничего из этого не выполняется, ошибка не выводится, onFailure тоже не выполняется - просто ничего не происходит*/
                    headtext.text = response.body()?.toString()
                    Toast.makeText(applicationContext, response.body()?.toString(), Toast.LENGTH_LONG).show()
                }

            }         )

        } catch (e: Exception) {
            headtext.text = "Exc: $e"
        }

Answer 1

First, there is no need to write nullable types in the interface.
Call<List<Company?>?>
replace with
Call<List<Company>>
Well, the response from the server should come in json format, and not some tags.
If you want to clean it from unnecessary tags before parsing the result from the server, then:

interface OrgList {
    @GET("test.php/")
    fun getcompanyes(): Call<List<Company?>?>
}

replace with :
If you want to clean it from unnecessary tags before parsing the result from the server, then:

interface OrgList {
    @GET("test.php/")
    fun getcompanyes(): Call<ResponseBody>
}

and the orgs?.enqueue method get. ResponseBody.toString() to parse and remove unwanted tags. Further, the cleaned json can be parsed with Gson

Answer 2

You need to log the response from the server. You can use several tools for this:

1. Network Profiler
   
2. Stetho
   
3. OkHttp logging interceptor
   

And you are overdoing it with nullable types too much. No need to put a question mark on all models in a row)