Htykuut

I'm writing in Kotlin and trying to incorporate Retrofit2 into my code, using this call: https://en.wikipedia.org/w/api.php?action=query&format=json&list=search&srsearch=Hello

This is my interface:

interface MyApiService {

    companion object {

        val myApiService by lazy {

            RealiApiService.create()

        }



        private fun create(): MyApiService {

            val retrofit = Retrofit.Builder()

                    .addConverterFactory(GsonConverterFactory.create())

                    .baseUrl("https://en.wikipedia.org/w/")

                    .build()



            return retrofit.create(RealiApiService::class.java)

        }

    }



    fun executeCall(call: Call<Any>) {

        call.enqueue(object : Callback<Any> {

            override fun onResponse(call: Call<Any>, response: Response<Any>) {

                Log.d("response is ${response.body()}")

            }



            override fun onFailure(call: Call<Any>, t: Throwable) {

                Log.d("Throwable is $t")

            }

        })

    }



    @GET("api.php")

    fun searchArtist(@Query("action") action: String,

                     @Query("format") format: String,

                     @Query("list") list: String,

                     @Query("srsearch") srsearch: String):

            Call<Any>

}

And this is my MainActivity:

class MainActivity : AppCompatActivity() {



    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_main)

        beginSearch("Hello")

    }



    private fun beginSearch(srsearch: String) {

        val call = realiApiService.searchArtist("query", "json", "search", srsearch)



        call.enqueue(object : Callback<Any> {

            override fun onResponse(call: Call<Any>, response: Response<Any>) {

                Log.d("response is ${response.body()}")

            }



            override fun onFailure(call: Call<Any>, t: Throwable) {

                Log.d("Throwable is $t")

            }

        })



        //myApiService.executeCall(call)

    }

}

The code above works perfectly.
Do note, however, I have the exact same code in beginSearch and in MyApiService's executeCall(). If I comment out the line and use it instead of what I have now, I'll get "java.lang.IllegalArgumentException: Service methods cannot return void.", and I'm not sure why. What am I doing wrong?

executeCall shouldn't be a method of MyAPIService. Retrofit tries to handle it along with other methods and can't, because as the error message says "Service methods cannot return void". So it can't create the service and throws the exception. Without that line, myApiService is never created.

The interface passed to Retrofit should be just an interface (without implementations) and only contain request methods annotated with @GET/@POST/etc.

Just put it basically anywhere else.