如何等到服务绑定？

Question

I'm programing a Bluetooth Service for my application. I don't know a lot about services in android but I managed to start one and use it the way I want.

My problem comes just on the very start when I try to use a function from the service on the onCreate() method from Activity (It doesnt have enought time to bind the service).

I structurated the code into 3 classes:

• BluetoothService: Class that implements the service

  public class BluetoothService extends Service implements IScanService { private final IBinder bluetoothBinder = new BluetoothBinder(); @Override public IBinder onBind(Intent intent) { return bluetoothBinder; } public class BluetoothBinder extends Binder { public BluetoothService getService() { return BluetoothService.this; } } // Other functions }

• BluetoothActivity: Abstract class (for reusability) that handles bluetooth service connection.

   public abstract class BluetoothActivity extends AppCompatActivity { protected BluetoothService bluetoothService; protected volatile Boolean isBound = false; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Connecting to the service Intent intent = new Intent(this, BluetoothService.class); bindService(intent, connection, Context.BIND_AUTO_CREATE); } private ServiceConnection connection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName className, IBinder service) { BluetoothService.BluetoothBinder binder = (BluetoothService.BluetoothBinder) service; bluetoothService = binder.getService(); isBound = true; } @Override public void onServiceDisconnected(ComponentName className) { isBound = false; } }; // Other functions }

• ScanActivity: Activity class that extends from BluetoothActivity and use BluetoothService methods on 'onCreate()'.

Variable 'isBound' is intended to be use in order to know if the service is bound (or if we have to wait).

What I tried:

• Use 'wait()' and 'notify()' but didn't worked for me.
• Use 'while(!isBound)' to wait but the application just crash.
• Use handlers to wait x miliseconds. This worked but I know is not the way since the service may not be bound.

So my question is how can I wait on the 'onCreate()' method until 'isBound' gets true?

Answer 1

I just realized I can create two functions on BluetoothService and call them on onServiceConnected() and onServiceDisconnected() :

private ServiceConnection connection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName name, IBinder binder) {
        BluetoothActivity.this.onServiceConnected(name, (BluetoothService.BluetoothBinder) binder);
    }

    @Override
    public void onServiceDisconnected(ComponentName name) {
        BluetoothActivity.this.onServiceDisconnected(name);
    }
};

protected void onServiceConnected(ComponentName name, BluetoothService.BluetoothBinder binder){
    bluetoothService = binder.getService();
}

protected void onServiceDisconnected(ComponentName name){
    bluetoothService = null;
}

And then just override them on the extended class:

@Override
protected void onServiceConnected(ComponentName name, BluetoothService.BluetoothBinder binder) {
    super.onServiceConnected(name, binder);
    //TODO
}

@Override
protected void onServiceDisconnected(ComponentName name) {
    // TODO
    super.onServiceDisconnected(name);
}