How do I add jvm arguments and configure properties with IcedTea

[saurabhqhr]

I want to add few jvm arguments to support java 11 . These arguments are mostly related to access module & package. For example
--add-opens=java.base/sun.misc=ALL-UNNAMED .
I also want to set the default locale java.locale.providers to COMPAT,SPI
I have set this in the jnlp file but when I launch application using IcedTea , these configuration are not applied.

 <property name="java.locale.providers" value="COMPAT,SPI"/>
  <j2se version="11"  java-vm-args="--add-opens=java.base/sun.misc=ALL-UNNAMED"  />

I found another way to apply above configuration by adding it to the itw-modularjdk.args file located inside C:\Program Files\IcedTeaWeb\WebStart\bin. But updating itw-modularjdk.args file is not ideal solution for us, since all our clients needs to manually update their icedTea configuration.
Is there any way to solve the above problem programmatically ?

[janakmulani]

OpenWebStart allows specifying JVM args by declaring them in a JVM Args whitelist in the deployment.properties file.

[lherschi]

I do the same with --add-exports, see https://portal.incore.de/dss-portal.jnlp.
Are you sure that the modified JNLP file is also used? Maybe the old one from the cache is being used.