Exceptions, and how best to retry when a connection is reset?

Question

I have some code which connects to a URL to download a file, and then performs some processing on it. However, sometimes I am receiving the error java.net.SocketException:

Answer 1

This is the kind of thing that I'd rather let a bullet-proof connection pool handle for me rather than writing it myself.

Answer 2

I've been wired to think that swallowing an exception is always bad, but I think here, that's the only way to tell if the connection was indeed reset. I guess you are handling the exception according to your requirements, so that's all the matters.

But I would, however, make it so you don't swallow the last exception. If it fails three times, you'll want to rethrow that exception or fail gracefully somehow.

Answer 3

AOP and Java annotations should help. I would recommend a read-made mechanism from jcabi-aspects (I'm a developer):

@RetryOnFailure(attempts = 3, delay = 5)
public String load(URL url) {
  return url.openConnection().getContent();
}

You may also try RetryFunc from Cactoos.