Android™ Application Development - Bahar Ali Khan

Chapter 8: Working in the Background
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// Stop a service explicitly.
try {
Class serviceClass = Class.forName(service.getClassName());
stopService(new Intent(this, serviceClass));
} catch (ClassNotFoundException e) {}
If startService is called on a Service that’s already running, the Service’s onStart method will be
executed again. Calls to startService do not nest, so a single call to stopService will terminate it no
matter how many times startService has been called.
An Earthquake Monitoring Service Example
In this chapter, you’ll modify the Earthquake example you started in Chapter 5 (and continued to
enhance in Chapters 6 and 7). In this example, you’ll move the earthquake updating and processing
functionality into a separate Service component.
Later in this chapter, you’ll build additional functionality within this Service, starting by moving the
network lookup and XML parsing to a background thread. Later, you’ll use Toasts and Notifi cations to
alert users of new earthquakes.
1. Start by creating a new EarthquakeService that extends Service.
package com.paad.earthquake;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import java.util.Timer;
import java.util.TimerTask;
public class EarthquakeService extends Service {
}
@Override
public void onStart(Intent intent, int startId) {
// TODO: Actions to perform when service is started.
}
@Override
public void onCreate() {
// TODO: Initialize variables, get references to GUI objects
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
2. Add this new Service to the manifest by adding a new service tag within the application node.
3. Move the refreshEarthquakes and addNewQuake methods out of the Earthquake Activity
and into the EarthquakeService.