How would I create an asynchronous notification system using RESTful web services?

Question

I have a Java application which I make available via RESTful web services. I want to create a mechanism so clients can register for notifications of events. The rub is that th

Answer 1

If polling is not acceptable I would consider using web-sockets (e.g. see here). Though to be honest I like the idea suggested by user189423 of multipart content-type or chunked transfer-encoding as well.