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Android Build a Weather App (2015) Concurrency and Error Handling What To Do When the Network is Down

Ryan Lentz
Ryan Lentz
9,191 Points

Issue with Callback

I can't build the app because there is a problem with the Callback. Android Studio wants me to implement methods that would change the onFailure and onResponse methods, completely changing the code.

Error:(42, 41) error: <anonymous teamtreehouse.com.stormy.MainActivity$1> is not abstract and does not override abstract method onResponse(Call,Response) in Callback

package teamtreehouse.com.stormy;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.Toast;

import java.io.IOException;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;


public class MainActivity extends AppCompatActivity {

    public static final String TAG = MainActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String apiKey = "27974c4bc33201748eaf542a6769c3b7";
        double latitude = 37.8267;
        double longitude = -122.423;
        String forecastUrl = "https://api.forecast.io/forecast/" + apiKey +
                "/" + latitude + "," + longitude;

        if (isNetworkAvailable()) {
            OkHttpClient client = new OkHttpClient();
            Request request = new Request.Builder()
                    .url(forecastUrl)
                    .build();

            Call call = client.newCall(request);
            call.enqueue(new Callback() {
                @Override
                public void onFailure(Request request, IOException e) {

                }

                @Override
                public void onResponse(Response response) throws IOException {
                    try {
                        Log.v(TAG, response.body().string());
                        if (response.isSuccessful()) {
                        } else {
                            alertUserAboutError();
                        }
                    } catch (IOException e) {
                        Log.e(TAG, "Exception caught: ", e);
                    }
                }
            });
        }
        else {
            Toast.makeText(this, getString(R.string.network_unavailable_message),
                    Toast.LENGTH_LONG).show();
        }

        Log.d(TAG, "Main UI code is running!");
    }

    private boolean isNetworkAvailable() {
        ConnectivityManager manager = (ConnectivityManager)
                getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        boolean isAvailable = false;
        if (networkInfo != null && networkInfo.isConnected()) {
            isAvailable = true;
        }

        return isAvailable;
    }

    private void alertUserAboutError() {
        AlertDialogFragment dialog = new AlertDialogFragment();
        dialog.show(getFragmentManager(), "error_dialog");
    }
}

1 Answer

Seth Kroger
Seth Kroger
56,413 Points

The course uses an older version of OkHttp which has slightly different arguments in the Callback methods. You should use the ones suggested by the quick-fix. The only difference is the new versions include a reference to the Call, which you don't use anyway, so the code inside the methods should be the same.

Ryan Lentz
Ryan Lentz
9,191 Points

Thanks, Seth. I didn't think that it would work because of the required Call, but it does.