Alternative to Rx request using Retrofit

README.md

RetrofitTask

To implement it with custom callback just call

Call<GitHubUser> call = githubService.getUser(userId);

RetrofitTask task = new RetrofitTask<GitHubUser>(call, new RetrofitTask.RetrofitTaskCllback<GitHubUser>(){
    @Override
    public void onSuccess(GitHubUser response) {
        //Do Something
    }
    
    @Override
    public void onFailed() {
        //Do Something
    }
});
task.execute();

To implement it with default callback just call

Call<GitHubUser> call = githubService.getUser(userId);

RetrofitTask task = new RetrofitTask<>(call, new retrofit2.Callback<GitHubUser>() {
                @Override
                public void onResponse(@NonNull Call<GitHubUser> call, @NonNull Response<GitHubUser> response) {
                    //Do Something
                }

                @Override
                public void onFailure(@NonNull Call<GitHubUser> call, @NonNull Throwable t) {
                    //Do Something
                }
            });
task.execute();

For error handling you can just look at this : https://futurestud.io/tutorials/retrofit-2-simple-error-handling

RetrofitTask.java

public class RetrofitTask<T> extends AsyncTask<Void, Void, Object> {

    private static final String TAG = RetrofitTask.class.getSimpleName();

    private Callback<T> defaultCallback;
    private RetrofitTaskCallback<T> callback;
    private Call<T> call;

    public void execute() {
        super.execute();
    }

    public RetrofitTask(Call<T> call, RetrofitTaskCallback<T> callback) {
        this.call = call;
        this.callback = callback;
    }

    public RetrofitTask(Call<T> call, Callback<T> defaultCallback) {
        this.call = call;
        this.defaultCallback = defaultCallback;
    }

    @Override
    protected Object doInBackground(Void... voids) {
        try {
            return call.execute();
        } catch (Exception e) {
            return e;
        }
    }

    @Override
    protected void onPostExecute(Object o) {
        if (o instanceof Exception) {
            if (defaultCallback != null)
                defaultCallback.onFailure(call.clone(), (Exception) o);
            if (callback != null)
                callback.onFailed();
        } else {
            Response<T> response = (Response<T>) o;

            if (defaultCallback != null)
                defaultCallback.onResponse(call.clone(), response);

            if (response.isSuccessful()) {
                if (callback != null)
                    callback.onSuccess(response.body());
            } else {
                if (callback != null)
                    callback.onFailed();
            }
        }
    }

    public interface RetrofitTaskCallback<T> {

        void onSuccess(T response);

        void onFailed();

    }

}