Nrthugu

I have several repository classes in my code.

For example, this is UserRepository:

public class UserRepository {



public static String TAG = "UserRepository";



ApiService mApiService;



SharedPreferences mPrefs;

Context mContext;



RemoteDataSource<User> mRemoteDataSource;





public UserRepository() {

    mApiService = new RetrofitClient().getApiService();

    mContext = App.getAppContext();

    mPrefs = PreferenceManager.getDefaultSharedPreferences(mContext);

    mRemoteDataSource = new RemoteDataSource<>();

}



public RemoteDataSource getRemoteDataSource() {

    mRemoteDataSource.setIsLoading();

    Call<ApiResponse> userCall = mApiService.getUserInfo(mPrefs.getString(User.TOKEN_NAME, null));

    userCall.enqueue(new Callback<ApiResponse>() {

        @Override

        public void onResponse(Call<ApiResponse> call, Response<ApiResponse> response) {

            mRemoteDataSource.setIsLoaded();

            mRemoteDataSource.setData(response.body().getUser());

            mRemoteDataSource.setStatus(response.body().getStatus());

            mRemoteDataSource.setMessage(response.body().getMessage());

        }



        @Override

        public void onFailure(Call<ApiResponse> call, Throwable t) {

            Log.e(TAG, t.getMessage());

            mRemoteDataSource.setFailed(t.getMessage());

        }

    });



return mRemoteDataSource;

}



}

And this is BonusRepository:

public class BonusRepository {



public static String TAG = "BonusRepository";



ApiService mApiService;



SharedPreferences mPrefs;

Context mContext;



LiveData<Bonus> mBonus;

String mId;

RemoteDataSource<Bonus> mRemoteDataSource;



public BonusRepository(String id) {

    mId = id;

    mApiService = new RetrofitClient().getApiService();

    mContext = App.getAppContext();

    mPrefs = PreferenceManager.getDefaultSharedPreferences(mContext);

    mRemoteDataSource = new RemoteDataSource<>();

}



public RemoteDataSource getRemoteDataSource() {

    mRemoteDataSource.setIsLoading();

    Call<ApiResponse> bonusCall = mApiService.getBonus(mPrefs.getString(User.TOKEN_NAME, null), mId);

    bonusCall.enqueue(new Callback<ApiResponse>() {

        @Override

        public void onResponse(Call<ApiResponse> call, Response<ApiResponse> response) {

            mRemoteDataSource.setIsLoaded();

            mRemoteDataSource.setData(response.body().getBonus());

            mRemoteDataSource.setStatus(response.body().getStatus());

            mRemoteDataSource.setMessage(response.body().getMessage());

        }



        @Override

        public void onFailure(Call<ApiResponse> call, Throwable t) {

            Log.e(TAG, t.getMessage());

            mRemoteDataSource.setFailed(t.getMessage());

        }

    });

    return mRemoteDataSource;

}

}

getRemoteDataSource methods in both classes are equal, except

Call<ApiResponse> userCall = mApiService.getUserInfo(mPrefs.getString(User.TOKEN_NAME, null));

and mRemoteDataSource.setData(response.body().getUser()); in UserRepository

differs with:

Call<ApiResponse> bonusCall = ApiService.getBonus(mPrefs.getString(User.TOKEN_NAME, null), mId);

and mRemoteDataSource.setData(response.body().getBonus()); in BonusRepository.

In other repositories I have similar duplicate code.

I want to remove this duplications, but doesn't find any good solution.

What is the best way to DRY my code?

Create an abstract class parent to all your repositories' ones, and implement the getRemoteDataSource() method, calling a new abstract method, which will be the only specific one, in each specific implementation.

For instance:

public class AbstractRepository {



protected abstract Call<ApiResponse> performCall();



public RemoteDataSource getRemoteDataSource() {

    mRemoteDataSource.setIsLoading();

    Call<ApiResponse> userCall = performCall();

    userCall.enqueue(new Callback<ApiResponse>() {

        @Override

        public void onResponse(Call<ApiResponse> call, Response<ApiResponse> response) {

            mRemoteDataSource.setIsLoaded();

            mRemoteDataSource.setData(response.body().getUser());

            mRemoteDataSource.setStatus(response.body().getStatus());

            mRemoteDataSource.setMessage(response.body().getMessage());

        }



        @Override

        public void onFailure(Call<ApiResponse> call, Throwable t) {

            Log.e(TAG, t.getMessage());

            mRemoteDataSource.setFailed(t.getMessage());

        }

    });



return mRemoteDataSource;

}



}

And then you can perform something like:

public class UserRepository extends AbstractRepository {



public static String TAG = "UserRepository";



ApiService mApiService;



SharedPreferences mPrefs;

Context mContext;



RemoteDataSource<User> mRemoteDataSource;



public UserRepository() {

    mApiService = new RetrofitClient().getApiService();

    mContext = App.getAppContext();

    mPrefs = PreferenceManager.getDefaultSharedPreferences(mContext);

    mRemoteDataSource = new RemoteDataSource<>();

}



protected Call<ApiResponse> performCall() {

    return mApiService.getUserInfo(mPrefs.getString(User.TOKEN_NAME, null));

}

}

I let you adapt to your needs, but this is the best solution.