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

Richard Opalka ropalka at
Wed Aug 16 21:03:36 UTC 2017

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.


On Wed, Aug 16, 2017 at 10:30 PM, Tom Hood <tom.w.hood at> 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
> 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/ by adding
> --add-exports=java.base/
> 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/ --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/ --add-exports
> java.desktop/ --add-exports
> java.desktop/sun.awt.dnd=ALL-UNNAMED --add-exports
> java.base/ --add-exports=java.base/
> 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
> Add-Exports: java.base/
> That doesn't appear to be taking affect.  Am I using it incorrectly?
> Thanks,
> -- Tom

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

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