A form of pattern matching and switch expression has already made it to the language as of JDK 14. Those are paving the way for full blown pattern matching and sealed types:

https://cr.openjdk.java.net/~briangoetz/amber/datum.html

https://openjdk.java.net/jeps/360

Java aren't fixing nulls, IMHO. They are making it worse.

How are they making it worse?

In any case, there already exist solutions in place:

https://checkerframework.org/manual/#example-use

https://github.com/uber/NullAway

The code ends up looking like:

  Optional<Integer> foo;

  //....

  if (foo != null) {
      foo.and_then(new Consumer () {
            function accept(Integer foo) {

            }
      });
  }

I would never assign null to an Optional nor use a library that returned one.

To ensure assignment before use make it final.