If you follows these steps to implement OKHTTP, then definitely you'll call multiple API on multiple screen by applying only two lines of code
UpdateListener updateListener = new UpdateListener(HitAPIActivity.this, baseHTTPRequest);
updateListener.getJsonData();
Step 1:
baseHTTPRequest = new BaseHTTPRequest();
    //    baseHTTPRequest.setURL("https://api.geonames.org/citiesJSON?north=44.1&south=-9.9&east=-22.4&west=55.2&lang=de&username=demohttps://api.geonames.org/citiesJSON?north=44.1&south=-9.9&east=-22.4&west=55.2&lang=de&username=demo");
baseHTTPRequest.setURL("http://jsonparsing.parseapp.com/jsonData/moviesDemoItem.txt");
        baseHTTPRequest.setRequestCode(reqType);
        baseHTTPRequest.setCachedRequired(true);
        UpdateListener updateListener = new UpdateListener(HitAPIActivity.this, baseHTTPRequest);
        updateListener.executeRequest();
Step 2 : Create a request class
/**
 * Created by Deepak Sharma on 4/7/16.
 * This is a HTTP request class which has the basic parameters.
 * If you wants to add some more parameters, please make a subclass of that class
 * and add with your subclass. Don't modify this class.
 */
 public class BaseHTTPRequest<T> {
    private Context context;
    private String URL;
    private int requestCode;
    private List<T> listParameters;
    private String header;
    private boolean isCachedRequired;
    public Context getContext() {
        return context;
    }
    public void setContext(Context context) {
        this.context = context;
    }
    public void setURL(String URL) {
        this.URL = URL;
    }
    public String getURL() {
        return URL;
    }
    public int getRequestCode() {
        return requestCode;
    }
    public void setRequestCode(int requestCode) {
        this.requestCode = requestCode;
    }
    public List<T> getListParameters() {
        return listParameters;
    }
    public void setListParameters(List<T> listParameters) {
        this.listParameters = listParameters;
    }
    public String getHeader() {
        return header;
    }
    public void setHeader(String header) {
        this.header = header;
    }
    public boolean isCachedRequired() {
        return isCachedRequired;
    }
    public void setCachedRequired(boolean cachedRequired) {
        isCachedRequired = cachedRequired;
    }
}
step 4 : Create a listener class
import android.util.Log;
import com.google.gson.Gson;
import java.io.IOException;
import dxswifi_direct.com.wifidirectcommunication.base.model.request.BaseHTTPRequest;
import okhttp3.Call;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Callback;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
/**
 * Created by Deepak Sharma on 4/7/16.
 * @email : dpsharma.sharma1@gmail.com
 * This is a Simple java class which will help you for HTTP request/response and it will
 * throw the response to your correspondance activity.
 */
public class UpdateListener {
    private OnUpdateViewListener onUpdateViewListener;
    OkHttpClient okHttpClient = new OkHttpClient();
    BaseHTTPRequest mRequestModel;
    private String mURL = null;
    private Request mRequest = null;
    public interface OnUpdateViewListener {
        void updateView(String responseString, boolean isSuccess,int reqType);
    }
    public UpdateListener(OnUpdateViewListener onUpdateView, final BaseHTTPRequest requestModel) {
        this.mRequestModel = requestModel;
        this.onUpdateViewListener = onUpdateView;
        if (requestModel.isCachedRequired())
        {
            /*File httpCacheDirectory = new File(requestModel.getContext().getCacheDir(), "responses");
            Cache cache = null;
            cache = new Cache(httpCacheDirectory, 10 * 1024 * 1024);
            if (cache != null) {
                okHttpClient.setCache(cache);
            }*/
        }
        /*mURL = null;
        if (requestModel.getListParameters()!=null && requestModel.getListParameters().size()>0)
        {
            HttpUrl.Builder urlBuilder = HttpUrl.parse(requestModel.getURL()).newBuilder();
            List<RequestParameter> requestParameters = requestModel.getListParameters();
            for (int i=0; i<requestParameters.size();i++)
            {
                urlBuilder.addQueryParameter(requestParameters.get(i).getKey(),requestParameters.get(i).getValue());
            }
            mURL = urlBuilder.build().toString();
        }
        else
        {
            mURL = requestModel.getURL();
        }*/
            mURL = requestModel.getURL();
        if (mRequestModel.getListParameters()!=null && mRequestModel.getListParameters().size()>1)
        {
            MediaType JSON = MediaType.parse("application/json; charset=utf-8");
            mRequest = new Request.Builder()
                    .url(mURL)
                    .post(RequestBody.create(JSON, new Gson().toJson(BaseHTTPRequest.class)))
                    .build();
        }
        else
        {
            mRequest = new Request.Builder()
                    .url(mURL)
                    .build();
        }
    }
    public void executeRequest()
    {
        Call call = okHttpClient.newCall(mRequest);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                e.printStackTrace();
                onUpdateViewListener.updateView(NetworkException.getErrorMessage(e), false, mRequestModel.getRequestCode());
            }
            @Override
            public void onResponse(Call call, Response response) throws IOException {
                if (!response.isSuccessful()) {
                    // You can also throw your own custom exception
                    throw new IOException("Unexpected code " + response);
                } else {
                    Log.i("Response:",response.toString());
                    Log.i("Response body:",response.body().toString());
                    Log.i("Response message:",response.message());
                    onUpdateViewListener.updateView(response.body().string(),true, mRequestModel.getRequestCode());
                }
                // do something wih the result
            }
        });
    }
}
step 5 : From the activity you requesting, implement listener
public class HitAPIActivity extends AppCompatActivity implements View.OnClickListener, UpdateListener.OnUpdateViewListener{
@Override
    public void updateView(final String responseString, boolean isSuccess, int reqType) {
if (isSuccess)
        {
if (!responseString.contains("failure")
                    && !responseString.contains("Error")) {
                // Handle request on the basis of Request Type.
                switch (reqType) {
                    case ApiConstants.GET_CONTACTS:
break;
default:
break;
}
}
}
}