Allow configuration of SpringCloudCommandRouter with a provided XStreamSerializer

[martijnvanderwoud]

The serializer used by the SpringCloudCommandRouter is hard-coded.

protected final XStreamSerializer serializer = XStreamSerializer.builder().build();

So far, I have not found a way to provide my own serializer. I would like to do so, since the hardcoded one produces this warning: "Security framework of XStream not initialized, XStream is probably vulnerable."

[smcvb]

Good point @martijnvanderwoud. It was hard coded to XStream as it is dedicated to serializing the CommandFilter which is shared with the other instances which will not go down too well with something like the JacksonSerialzier. At that point the warning didn't occur yet, hence why it's their.

Should be easy enough to adjust this though. I would suggest to add a dedicated builder method in the SpringCloudCommandRouter.Builder which allows you to set the XStreamSerializer. That way, users have the ability to adjust the XStreamSerializer to a version which has an initialized XStream instance.

[martijnvanderwoud]

I agree Steven, would you like me to submit a PR for this? Might be a while before I find some time for this but it does not appear to be very complicated

[smcvb]

If you would have the time to provide a PR @martijnvanderwoud, that would be great!

[martijnvanderwoud]

Thanks for fixing this @smcvb, sorry that I did not make time to create a PR (this was still on my todo list, but has been there for ages)