Integrating wordpress into a Java based application

We have a Java / Spring based web application and would like to use WordPress as our Blogging part of the website. The main issue is probably user authentication and we would like the java web application to be the main control

I've looked around now and it looks like WP is using cookies to check if a user is logged in or not. It is theoretically possible to write some additional code in a local WP Core file to have some kind of REST API, and Java can call it to log into WP, but I have never done that before or seen good examples.

if you have any suggestions that would be awesome Thanks a lot!