Java 9 was releaseed 2017-09-21. It is not an LTS release and was obsoleted at the release of Java 10 on 2018-03-20.
Resources
- JDK 9.0.4 General-Availability Release
- Java Platform, Standard Edition What’s New in Oracle JDK 9
- Java Platform, Standard Edition Oracle JDK 9 Migration Guide
- WTF, Java 9?!
Significant Changes from Java 8
- JEP 200: Introduced the modular JDK.
- JEP 243: Java-Level JVM Compiler Interface
- First prototyped in Java 8, this is the foundation for things like Graal: language compilers written in Java that target the JVM at runtime. It's an experimental feature in Java 9, and the actual API is changed in Java 11.
- Removed
javacsupport for--source/--target5/1.5. - Static convenience factory methods for collections, with new immutable implementations.