Retry Task Framework

Question

I have a number of situations where I need to retry a task n-times if it fails (sometimes with some form of back-off-before-retry logic). Generally, if an exception is thrown, the task should be retried up to the max-retry count.

I can easily write something to do this fairly generically, but not wanting to re-invent the wheel I was wondering if anyone can recommend any frameworks for this. The only thing I have been able to find is: Ant Retry but I don't want to use Ant tasks directly in my application.

Thanks

Answer 1

Check out Failsafe. It's a simple, zero-dependency library for performing retries, and supports synchronous and asynchronous retries, Java 8 integration, event listeners, integration with other async APIs, etc:

RetryPolicy retryPolicy = new RetryPolicy()   .handle(ConnectException.class, SocketException.class);   .withMaxRetries(3);  Connection connection = Failsafe.with(retryPolicy).get(() -> connect()); 

Doesn't get much easier.

Answer 2

You can use RetriableTasks as outlined in this post: Retrying Operations in Java. You can quite easily change its waiting algorithm if you like.

Sample code:

//creates a task which will retry 3 times with an interval of 5 seconds RetriableTask r = new RetriableTask(3, 5000, new Callable(){     public Object call() throws Exception{         //put your code here     } }); r.call();