Retrofit 2.0 how to get deserialised error response.body

Question

I\'m using Retrofit 2.0.0-beta1.

In tests i have an alternate scenario and expect error HTTP 400

I would like to have retrofit.Respons

Answer 1

In https://stackoverflow.com/a/21103420/2914140 and https://futurestud.io/tutorials/retrofit-2-simple-error-handling this variant is shown for Retrofit 2.1.0.

call.enqueue(new Callback<MyResponse>() {
    @Override
    public void onResponse(Call<MyResponse> call, Response<MyResponse> response) {
        if (response.isSuccessful()) {
            ...
        } else {
            Converter<ResponseBody, MyError> converter
                    = MyApplication.getRetrofit().responseBodyConverter(
                    MyError.class, new Annotation[0]);
            MyError errorResponse = null;
            try {
                errorResponse = converter.convert(response.errorBody());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

Answer 2

try{
                ResponseBody response = ((HttpException) t).response().errorBody();
                JSONObject json = new JSONObject( new String(response.bytes()) );
                errMsg = json.getString("message");
            }catch(JSONException e){
                return t.getMessage();
            }
            catch(IOException e){
                return t.getMessage();
            }

Answer 3

if(!response.isSuccessful()) {
    StringBuilder error = new StringBuilder();
    try {
        BufferedReader bufferedReader = null;
        if (response.errorBody() != null) {
            bufferedReader = new BufferedReader(new InputStreamReader(
                    response.errorBody().byteStream()));

            String eLine = null;
            while ((eLine = bufferedReader.readLine()) != null) {
                error.append(eLine);
            }
            bufferedReader.close();
        }

    } catch (Exception e) {
        error.append(e.getMessage());
    }

    Log.e("Error", error.toString());
}

Answer 4

 @Override
 public void onResponse(Call<Void> call, retrofit2.Response<Void> response) {
            if (response.isSuccessful()) {

            //Do something if response is ok
            } else {

                JsonParser parser = new JsonParser();
                JsonElement mJson = null;
                try {
                    mJson = parser.parse(response.errorBody().string());
                    Gson gson = new Gson();
                    MyError errorResponse = gson.fromJson(mJson, MyError.class);
                } catch (IOException ex) {
                    ex.printStackTrace();
                }

            }

Answer 5

If you use Kotlin another solution could be just create extension function for Response class:

inline fun <reified T>Response<*>.parseErrJsonResponse(): T?
{
    val moshi = MyCustomMoshiBuilder().build()
    val parser = moshi.adapter(T::class.java)
    val response = errorBody()?.string()
    if(response != null)
        try {
            return parser.fromJson(response)
        } catch(e: JsonDataException) {
            e.printStackTrace()
        }
    return null
}

Usage

val myError = response.parseErrJsonResponse<MyErrorResponse>()
if(myError != null) {
   // handle your error logic here
   // ...
}

Answer 6

I did it this way for asynchronous calls using Retrofit 2.0-beta2:

@Override
public void onResponse(Response<RegistrationResponse> response, 
                       Retrofit retrofit) {
    if (response.isSuccess()) {
        // Do success handling here
    } else {
        try {
            MyError myError = (MyError)retrofit.responseConverter(
                    MyError.class, MyError.class.getAnnotations())
                .convert(response.errorBody());
            // Do error handling here
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}