What if Java had Kotlin-style null-safety without migrating your Spring Boot project to Kotlin?

I've been building JADEx — a source-to-source compiler that adds two things Java has always been missing: null-safety and final-by-default semantics. No JVM changes, no runtime dependency, just safer Java. The problem If you've worked on a large Spring Boot codebase, you've seen this everywhere: public String getUsername(User user) { if (user == null) return null; if (user.getProfile() == null) return null; return user.getProfile().getUsername(); } The usual o