CountDownLatch Example

Countdown.java

private class MyServiceFilter implements ServiceFilter {    	
	@Override 
	public void handleRequest(final ServiceFilterRequest request, final NextServiceFilterCallback nextServiceFilterCallback,
			final ServiceFilterResponseCallback responseCallback) {
		
		nextServiceFilterCallback.onNext(request, new ServiceFilterResponseCallback() {				
			@Override
			public void onResponse(ServiceFilterResponse response, Exception exception) {				
				StatusLine status = response.getStatus();
				int statusCode = status.getStatusCode();						
				if (statusCode == 401) {
					final CountDownLatch latch = new CountDownLatch(1);
					//Get the current activity for the context so we can show the login dialog
					AuthenticationApplication myApp = (AuthenticationApplication) mContext;
					Activity currentActivity = myApp.getCurrentActivity();
					mClient.setContext(currentActivity);					
					currentActivity.runOnUiThread(new Runnable() {
						@Override
						public void run() {
							mClient.login(mProvider, new UserAuthenticationCallback() {											
								@Override
								public void onCompleted(MobileServiceUser user, Exception exception,
										ServiceFilterResponse response) {
									if (exception == null) {
										//Update the request object
										latch.countDown();																					
									} else {
										Log.e(TAG, "User did not login successfully after 401");
									}
								}
							});
						}
					});
					try {
						latch.await();
					} catch (InterruptedException e) {
						Log.e(TAG, "Interrupted exception: " + e.getMessage());
						return;
					}					
					nextServiceFilterCallback.onNext(request, responseCallback);																										
				} else {
					responseCallback.onResponse(response, exception);
				}
			}
		});
	}
}