Basic IntentService Example

The 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.