Basic IntentService Example
suggest changeThe abstract class IntentService
is a base class for services, which run in the background without any user interface. Therefore, in order to update the UI, we have to make use of a receiver, which may be either a BroadcastReceiver
or a ResultReceiver
:
- A
BroadcastReceiver
should be used if your service needs to communicate with multiple components that want to listen for communication. - A
ResultReceiver
: should be used if your service needs to communicate with only the parent application (i.e. your application).
Within the IntentService
, we have one key method, onHandleIntent()
, in which we will do all actions, for example, preparing notifications, creating alarms, etc.
If you want to use you own IntentService
, you have to extend it as follows:
public class YourIntentService extends IntentService {
public YourIntentService () {
super("YourIntentService ");
}
@Override
protected void onHandleIntent(Intent intent) {
// TODO: Write your own code here.
}
}
Calling/starting the activity can be done as follows:
Intent i = new Intent(this, YourIntentService.class);
startService(i); // For the service.
startActivity(i); // For the activity; ignore this for now.
Similar to any activity, you can pass extra information such as bundle data to it as follows:
Intent passDataIntent = new Intent(this, YourIntentService.class);
msgIntent.putExtra("foo","bar");
startService(passDataIntent);
Now assume that we passed some data to the YourIntentService
class. Based on this data, an action can be performed as follows:
public class YourIntentService extends IntentService {
private String actvityValue="bar";
String retrivedValue=intent.getStringExtra("foo");
public YourIntentService () {
super("YourIntentService ");
}
@Override
protected void onHandleIntent(Intent intent) {
if(retrivedValue.equals(actvityValue)){
// Send the notification to foo.
} else {
// Retrieving data failed.
}
}
}
The code above also shows how to handle constraints in the OnHandleIntent()
method.