Winston Liek wrote:I only know how to do web apps.
This seems like a good opportunity to learn something new.
I don't think what you want exists. I also don't understand what it would mean. A web app communicates with a server to get to a database. A standalone app is typically not concerned with the network so frequently. So it would be an application with a different approach.
The fundamental architecture of a webapp is generally different than that of a desktop app, although for GUI apps using MVC there's a certain functional correspondence. But even using JSF, which reduces a lot of the UI to declarative forms (which are easier to convert to different platforms via an automated tool), it would be a challenge. I think that JSF did have such ambitions at one time, but more recently it has become more HTML-centric.
If you did go the Spring Boot approach, you wouldn't be the first. One of the VMWare products included Tomcat server provisioned with a VMWare VM machine configuration and control app. Casual users wouldn't have even realized that it had Tomcat in it, in fact.
It seems a bit of overkill to go that route, but it's one way recycle a lot of web-specific code when the only other option would be a completely designed-from-scratch Java app.
When it comes to destroying a civilization, gas chambers cannot hold a candle to echo chambers.