Trouble accessing class field values inside a JobIntentService

Question

I'm trying to use the JobIntentService on Android and I'm having trouble accessing the class fields inside the onHandleWork method. My discoverable field always seems to be null inside the onHandleWork method.

Here is my JobIntentService class:

import android.content.Context;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v4.app.JobIntentService;
import com.orhanobut.logger.AndroidLogAdapter;
import com.orhanobut.logger.Logger;
import io.hypertrack.smart_scheduler.Job;
import io.hypertrack.smart_scheduler.SmartScheduler;

public class NetworkCheckService extends JobIntentService {
  private static final int jobId = 1;

  private Settings settings;
  private NetworkInformation networkInfo;
  private Networks networks;
  private Discoverable discoverable;

  {
    Logger.addLogAdapter(new AndroidLogAdapter());
  }

  // Needs an empty constructor for some reason.
  public NetworkCheckService() {
  }

  public NetworkCheckService(Context context) {
    this.settings = new Settings(context);
    this.networkInfo = new NetworkInformation(context);
    this.networks = new Networks(context, networkInfo);
    this.discoverable = new Discoverable(settings, networks);
  }

  private Discoverable getDiscoverable() {
    return discoverable;
  }

  static void enqueueWork(Context context, Intent work) {
    enqueueWork(context, NetworkCheckService.class, jobId, work);
  }

  public void onHandleWork(@NonNull Intent intent) {
    Logger.d(discoverable); // discoverable is null
    Discoverable foo = getDiscoverable(); // foo is null
  }

}

My main activity class:

public class MainActivity extends AppCompatActivity {

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

    NetworkCheckService networkCheckService = new NetworkCheckService(this);
    networkCheckService.enqueueWork(this, new Intent());
  }

}

Answer 1

We should not create any constructor in service class. It does by the android system. This is the reason your member variables becoming null. Better to initialize them inside onHandleWork method.