Java9 is the major version of java. it contains some important topics
like
1) Private methods inside an interface
2) Try with resource enhancement
3) Diamond resource enhancement
4)Safe Varags Annotation enhancement
5)Factory methods for creating unmodified collections
6)Stream API enhancement
7)JShell
8)The Java Platform Module System(JPMS)
9)JLink
10)Process API updates
11)Http/2Client