Dear Thinnaklit,
If you are using Tomcat alone as the primary web server without Apache or Ngnix, you can follow the steps shown in the Hermes documentation.
And some helpful info. about setup SSL in tomcat can be found in below website.
If you have any further enquiry, please feel free to ask.
Thanks for your interest in Hermes2+ Business Messaging Gateway.
Best Rgds,
Kenneth