Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
If you have your JBoss server directly terminating TLS, then you may have imported the previous certificate by converting it to a different format (thinking of other Java-based web servers which often don’t understand PEM format directly). In that case, the process would need to be repeated every time you renew the certificate in order for the JBoss server to use the new certificate. (If so, you can use a --deploy-hook script with Certbot to automate this step.)
Yes, every renewal is a new certificate which must be reimported into your web server in the same way as the original was imported. I don’t think a tutorial that omits this information is very helpful!
You can write a script to automate the process and then specify it to Certbot with --deploy-hook; after this, the script will be run automatically every time Certbot performs a renewal.