Ref. JEP 12 - Preview Language and VM Features

Alex Buckley alex.buckley at
Wed Mar 7 01:49:11 UTC 2018

On 3/6/2018 5:00 PM, David Holmes wrote:
> The JEP defines a "launcher flag" --enable-preview but it is unclear
> whether this is truly a launcher flag or a VM flag? Is the VM expected
> to process the --enable-preview flag and accept it via the JNI
> invocation API? Or does the launcher translate --enable-preview into a
> suitable -XX VM flag?
> If the above is considered too implementation oriented for the JEP then
> at a minimum the JEP needs to clarify whether you can enable preview
> features via the JNI invocation API.

Let's proceed by assuming that you cannot enable preview features via 
the JNI Invocation API.


More information about the jdk-dev mailing list