Not a "language" enhancement per se, but I find Collection Factory Methods a nice improvement.

https://www.sitepoint.com/ultimate-guide-to-java-9/#collecti...

There are a few language enhancements. It's true the 9 isn't a revolutionary release for the Java language, but there are several useful changes.

This[1] is the best summary of what is in the release that I've read. The first section discusses language enhancements. Lots of cross references to JSRs and other material.

[1] https://www.sitepoint.com/ultimate-guide-to-java-9

Don't worry, pattern matching and data classes should be coming in one of the Java 9 feature releases (6 month cycle).

They'll probaby cherry pick some other language features along the way to Java 10.

There is not going to be a Java 10. The next version of Java will be 18.3, to be released in March '18, followed by a release every 6 months. Those will not be "Java 9 feature releases" but "major" Java releases.

modules are a massive enhancement that will benefit kotlin as well as any other jvm language

I wouldn't classify that as _massive_ , but it definitely pleases the maven/gradle dudes.

Still, no major language enhancements...

well, most of my java projects tend to be very broad in scope, so in those cases, it can potentially make a major impact in systems and API designs.. I'm being optimistic!

Just yesterday I was giving support to a Java 1.4 project....