jpackage: support for environment variables in --java-options

[Serban Iordache]

Not sure if it was clear from my previous messages, but what I am asking
for is that the environment variables are expanded with the values they
have on the user's machine (not on the machine where jpackage has been
executed).

Am Di., 1. Sept. 2020 um 08:37 Uhr schrieb Serban Iordache <
serban.iordache at gmail.com>:

> Thanks, Michael!
>
> I maintain two Gradle plugins that help creating custom images and
> packages with jlink and jpackage (
> https://github.com/beryx/badass-jlink-plugin and
> https://github.com/beryx/badass-runtime-plugin). The request for
> supporting environment variables came from my users. They have actually
> other use cases than the one involving $HOME, which I used in my example.
> For some of these use cases, it's more difficult to find a solution that
> doesn't require environment variables. That's why I'm asking for a generic
> way of dealing with this issue.
>
> Supporting environment variables in --java-options may also be a solution
> for https://bugs.openjdk.java.net/browse/JDK-8250950 (allowing users to
> specify their own memory requirements), for example using: --java-options
> "-Xmx$MY_MAX_JAVA_HEAP".
>
> Am Mo., 31. Aug. 2020 um 22:14 Uhr schrieb Michael Hall <
> mik3hall at gmail.com>:
>
>>
>>
>> > On Aug 31, 2020, at 3:07 PM, Michael Hall <mik3hall at gmail.com> wrote:
>> >
>> >
>> >
>> >> On Aug 29, 2020, at 3:37 AM, Serban Iordache <
>> serban.iordache at gmail.com> wrote:
>> >>
>> >> Hi,
>> >>
>> >> Is there a way to pass values from environment variables when using
>> >> --java-options?
>> >>
>> >> It would be nice to be able to write something like this:
>> >> --java-options "-DmyAppData=$HOME/.myData”
>> >
>> > For this couldn’t you just pass the parameter without the path and then
>> add it later?
>> >
>> > -DmyAppData=/.myData
>> >
>> > final String HOME = System.getProperty(“user.home”);
>> >
>> System.setProperty(“myAppData”,HOME+System.getProperty(myAppData),”.myData”);
>>
>> For user data these days don’t many platforms have preferred places for
>> user data other than user home?
>> It has occurred to me it might be nice of java had an API that actually
>> automatically gave you the correct directory for a given platform to put
>> your data. Maybe different locations for different types of user data.
>>
>>