2-) retrofitte timeout süresi ayarlama -> ServiceGenerator.java -> son hali bunu kullan

package com.webpos.ramazan.rmos.rmossay.WebServis;
import com.webpos.ramazan.rmos.rmossay.MainActivity;
import java.util.concurrent.TimeUnit;
import okhttp3.OkHttpClient;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
public class ServiceGenerator {
    public static String baseUrl = MainActivity.MyWebServis;
    public static Retrofit retrofit;
    private static Retrofit.Builder builder = new Retrofit.Builder().baseUrl(baseUrl).addConverterFactory(GsonConverterFactory.create());
    private static OkHttpClient.Builder httpClient = new OkHttpClient().newBuilder();
    public static <S> S createService(Class<S> serviceClass) {

        httpClient.connectTimeout(30, TimeUnit.SECONDS);
        httpClient.readTimeout(30, TimeUnit.SECONDS);
        httpClient.writeTimeout(30, TimeUnit.SECONDS);

        builder.client(httpClient.build());
        retrofit = builder.build();
        return retrofit.create(serviceClass);
    }
}

1-) Android Yeni -  retrofit2

http://androidce.blogspot.com.tr/2016/09/retrofit-2-kullanm-l.html

// diğer

fisModelCall.enqueue( new Callback<FisModel>() {// burası olmasada olur iki iş yapıyoruz
    @Override
    public void onResponse(Call<FisModel> call, Response<FisModel> response) {
        if (response != null & response.isSuccessful()) {
            FisModel fisModels = response.body();
            Genel.fisno = fisModels.getModel().get(0).getFisno();
        } else {
            Gson gson = new Gson();
            Type type = new TypeToken<FisModel>() {
            }.getType();
            FisModel errorResponse = gson.fromJson(response.errorBody().charStream(), type);
            Toast.makeText(getContext(), "" + errorResponse.getMessage(), Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public void onFailure(Call<FisModel> call, Throwable t) {
        Toast.makeText(getContext(), "Yüklenemedi2...!!" + t.getMessage(), Toast.LENGTH_SHORT).show();
    }
});