RFE to re-purpose option --version:<version>

[Mandy Chung]

> On Aug 8, 2016, at 8:51 AM, Paul Benedict <pbenedict at apache.org> wrote:
> 
> However, I would like to propose bringing back the option with a different
> purpose. I would like to use --version:<version> as a validation check. I
> want Java to execute ONLY if the version specified matches the actual
> platform version. This would be a wonderful help to scripts that require a
> particular version of the Java platform, and should fail if the environment
> has been accidentally setup with the wrong Java platform version.
> 
> Examples:
> java --version:9
> java --version:9.1
> 
> AFAICT, the only way to do this now is to execute Java twice. Once to pipe
> --version to some find/grep command and check return code, and then execute
> java again if the check pass. Loading the runtime twice is not optimal,
> wouldn't you agree? Yet if you agree to this proposal, it would be a big
> win for script writers, I believe.

Have you considered checking the JAVA_VERSION property in $JAVA_HOME/release file?  jlink creates the `release` file containing certain properties about the runtime image.

Mandy