How to POST raw whole JSON in the body of a Retrofit request?

Question

This question may have been asked before but no it was not definitively answered. How exactly does one post raw whole JSON inside the body of a Retrofit request?

See

Answer 1

Things required to send raw json in Retrofit.

1) Make sure to add the following header and remove any other duplicate header. Since, on Retrofit's official documentation they specifically mention-

Note that headers do not overwrite each other. All headers with the same name will be included in the request.

@Headers({"Content-Type: application/json"})

2) a. If you are using a converter factory you can pass your json as a String, JSONObject, JsonObject and even a POJO. Also have checked, having ScalarConverterFactory is not necessary only GsonConverterFactory does the job.

@POST("/urlPath")
@FormUrlEncoded
Call myApi(@Header("Authorization") String auth, @Header("KEY") String key, 
                     @Body JsonObject/POJO/String requestBody);

2) b. If you are NOT using any converter factory then you MUST use okhttp3's RequestBody as Retrofit's documentation says-

The object will also be converted using a converter specified on the Retrofit instance. If no converter is added, only RequestBody can be used.

RequestBody requestBody=RequestBody.create(MediaType.parse("application/json; charset=utf-8"),jsonString);

@POST("/urlPath")
@FormUrlEncoded
Call myApi(@Header("Authorization") String auth, @Header("KEY") String key, 
                 @Body RequestBody requestBody);

3) Success!!