Manifest Add-Exports vs. command line --add-exports

[Richard Opalka]

Hi Tom,

   Add-Exports option in manifest is used if and only if jar is
executed via 'java -jar your.jar' command.
The manifest Add-Exports option is ignored for jars on classpath.

Rio

On Wed, Aug 16, 2017 at 10:30 PM, Tom Hood <tom.w.hood at gmail.com> wrote:

> Hi,
>
> I need a little help understanding the difference between "Add-Exports:" in
> a jar's manifest vs. the command line arg --add-exports.  I can get
> --add-exports to work, but not Add-Exports.
>
> JDK Version: 9 build 181 windows 64
>
> Slide 23 of http://openjdk.java.net/projects/jigsaw/talks/prepare-
> for-jdk9-j1-2016.pdf seems to suggest Add-Exports in the manifest as an
> alternative to --add-exports
>
> Our webstart-launched app requires a long list of --add-module and/or
> --add-exports command line options.  The list is long enough that it
> exceeds a limit on number of args and webstart fails to launch the app with
> the popup "too many args to run".
>
> Specifically, I was trying to allow jai_imageio.jar (1.0_01) to access
> java.base/sun.security.action by adding
> --add-exports=java.base/sun.security.action=ALL-UNNAMED
> to the java-vm-args in the jnlp.  However, that one additional arg pushed
> it over the edge and exceeded the limit.
>
> This is the full j2se element in our jnlp:
>
> <j2se  version="1.9+" initial-heap-size="32m" max-heap-size="3072m"
>      java-vm-args="--add-modules=java.corba --add-exports
> java.desktop/com.sun.java.swing.plaf.windows=ALL-UNNAMED --add-exports
> java.desktop/sun.swing=ALL-UNNAMED --add-exports
> java.desktop/sun.awt=ALL-UNNAMED --add-exports
> java.desktop/sun.awt.image=ALL-UNNAMED --add-exports
> java.desktop/sun.awt.windows=ALL-UNNAMED --add-exports
> java.desktop/sun.awt.shell=ALL-UNNAMED --add-exports
> java.desktop/sun.awt.dnd=ALL-UNNAMED --add-exports
> java.base/sun.security.action=ALL-UNNAMED --add-exports=java.base/sun.se
> curity.action=ALL-UNNAMED"/>
>
> I then removed the last --add-exports to keep under the arg limit and
> instead added an Add-Exports line to the jai_imageio.jar
> META-INF/MANIFEST.MF
>
> Add-Exports: java.base/sun.security.action
>
> That doesn't appear to be taking affect.  Am I using it incorrectly?
>
> Thanks,
> -- Tom
>



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Richard Opalka
Principal Software Engineer
Red Hat JBoss Middleware
Mobile: +420 731 186 942
E-mail: ropalka at redhat.com