Call Java Asynchronous Method

Question

I already have one thread that should do the following work:

public class DetectionHandler extends TimerTask {

@Override
public void run() {
bluetoothAddresses = BluetoothModule.scanAddresses();
wiFiAddresses = WiFiModule.scanAddresses();
...//when scanning is finished, continue work
}

I would like this scan to be parallel. Therefore, I assume that I should use these two methods asynchronously. And when this scan is finished, I can continue to work in the DetectionHandler class.

I tried both BluetoothModule and WiFiModule implements Runnable, but no luck. Tnx

Answer 1

Using ExecutorService , you can write something like this:

ArrayList<Callable<Collection<Address>>> tasks = new ArrayList<Callable<Collection<Address>>>();
tasks.add(new Callable<Collection<Address>>() {
  public Collection<Address> call() throws Exception {
    return BluetoothModule.scanAddresses();
  }
});
tasks.add(new Callable<Collection<Address>>() {
  public Collection<Address> call() throws Exception {
    return WiFiModule.scanAddresses();
  }
});

ExecutorService executorService = Executors.newFixedThreadPool(2);
List<Future<Collection<Address>>> futures = executorService.invokeAll(tasks);

Answer 2

ExecutorService Executors FutureTask.

, get() . , ( ) - .

:

     FutureTask<List<Address>> btFuture =
       new FutureTask<List<Address>>(new Callable<List<Address>>() {
         public List<Address> call() {
           return BluetoothModule.scanAddresses();
       }});
     executor.execute(btFuture);

     FutureTask<List<Address>> wfFuture =
       new FutureTask<List<Address>>(new Callable<List<Address>>() {
         public List<Address> call() {
           return WifiModule.scanAddresses();
       }});
     executor.execute(wfFuture);

    btAddresses = btFuture.get(); // blocks until process finished
    wifiAddresses = wfFuture.get(); // blocks

, get . ExecutionException.