Desktop Application Security [on hold]

I’m developing a Hospital Information System using Java. However it’s a Desktop Application and not sure how to make it as secure as possible. Focussing particularly on data privacy and availability of the app.

I’ve looked at the Java Secure Coding guidelines https://www.oracle.com/technetwork/java/seccodeguide-139067.html , but not sure they’re within the scope of my project.

Any help would be much appreciated, Thanks.