Coming later in JDK 9: dropping support for javac -source/-target of 5/1.5 and older

[Joe Darcy]

Hello,

Preparatory work [1] has already occurred in JDK 9 for the implementation of

     JEP 182: Policy for Retiring javac -source and -target Options
     http://openjdk.java.net/jeps/182

in the release. According the policy described in this JEP, the javac in 
JDK 9 would only support -source and -target options in the set:

     {6/1.6, 7/1.7, 8/1.8, 9/1.9}

Consequently, -source/-target options like 5/1.5, 1.4, etc. will *not* 
be supported anymore. However, javac and related tools would still be 
able to recognize and process older classfiles.

Regards,

-Joe

[1] 8031651: Remove unneeded -source and -target flags in jdk repo 
regression tests
http://hg.openjdk.java.net/jdk9/dev/jdk/rev/6744e0c2459f

8031745: Remove unneeded/obsolete -source/-target options in javac 
tests, part 1
http://hg.openjdk.java.net/jdk9/dev/langtools/rev/b49771a49320