Things may have changed but I could never get certbot to work automatically to generate a java keystore. I have however just found a site that offers 12 month certs for $3.99/year (single domain and you have to pay for 5 years to get that price - A little under $20
https://www.ssls.com
creating the JKS with keystore explorer is easy enough - but thanks for getting back to me so quickly, much appreciated.
That said - can't take the server down until tonight, so don't know for sure its working, but the company offer a 30 day trial so I have until June 14th to pay, and they didn't even ask for card details up front. The cert will just stop working after that date if I don't pay. Will post back tomorrow if the cert works (or not)
