Retrofit 2.0 handling errors

I've been working in a personal Android application, to connect with the web service I use Retrofit 2.0 beta 3, while I was checking the process I found that some errors can't be handle for retrofit for example status error > 400 . To solved that I did a few changes that will be explained below.

Installation

For gradle installation:

compile 'com.squareup.retrofit2:retrofit:2.0.0-beta4'

Steps

I created RestClient that basically is a singleton class for the retrofit object.

In RestClient is a method to add an interceptor, just to send some values in the header.

 public OkHttpClient getOkHttpClient() {
        RequestInterceptor requestInterceptor = new RequestInterceptor();
        OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .addInterceptor(requestInterceptor)
                .build();
        return okHttpClient;
    }

Retrofit has a property that will let us know if the call to the service was successful.

@Override
public void onResponse(Response<TempError> response) {
    if(response.isSuccess()) {
        /// do something
    } else {
        /// Converter for errores
    }
}

To handle and error when the status > 400 , there is a custom class called Utils inside this class we have a method parseError that recives in parameter the Response<?> response, this is to convert the response and return our custom error.

public static TempError parseError(Response<?> response) {
    ///This converter create the base for custom error.
    Converter<ResponseBody, TempError> converter = RestClient.getsInstance().getRetrofit().responseBodyConverter(TempError.class, new Annotation[0]);
    TempError error;
    try {
        error = converter.convert(response.errorBody());
    } catch (IOException e) {
        return new TempError();
    }
    return error;
}

And our response methos is working in this way:

@Override
public void onResponse(Response<TempError> response) {
    if(response.isSuccess()) {
        /// do something
    } else {
        /// Converter for error
        TempError error = Utils.parseError(response).getError();
    }
}

Hope this help you, and if you have any question or suggestion let me.

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