Pass additional parameters to vm used by javaws

Get help with installation and configuration of OWS. Please post specific bug reports, pull requests, or source code extensions on github.
Candlejack
Posts: 2
Joined: 31 Mar 2026, 11:21

Pass additional parameters to vm used by javaws

Post by Candlejack »

Hi,

I want to pass some jvm args to a program started via jnlp. I am using OWS 1.13.0 on Ubuntu. I spent a few hours searching for a way to do this and came across different combinations of the same building blocks but got none of them working, so I hope someone here can give me a pointer.

In my specific case I want to pass -Dawt.useSystemAAFontSettings=lcd to the program. I tried the following things:

- add the property to javaws.vmoptions but this seems to only be applied to the launcher and the actual jvm/program itself
- define a global deployment.properties to define additional parameters there, the file gets read but all properties suggested to me by online search and AI bots were not recognized by OWS (logs say the property key is unknown). So maybe I would only need to find the proper key to use here to specify the above option as value. I also did add deployment.jvm.arguments.whitelist=-Dawt.useSystemAAFontSettings\=lcd to the properties file so the parameter should be allowed
- define deployment.jvm.arguments.whitelist=-Dawt.useSystemAAFontSettings\=lcd in my user specific deployment.properties under .confg/icead-tea and set/export the property as an environment variable using _JAVA_OPTIONS, JAVA_TOOL_OPTIONS or JAVAWS_WM_ARGS

In none of these cases did the command line shown in ps contain my java option.

Are there any additional resources listing the available deployment.properties? Is there another combination I should use? If you require any more information please let me know.

Janak Mulani
Posts: 1088
Joined: 24 Mar 2020, 13:37

Re: Pass additional parameters to vm used by javaws

Post by Janak Mulani »

You can pass a JVM argument to the JVM that starts the App specified in the Jnlp file in the following ways:

1. In the Jnlp file:

Code: Select all

 <<j2se version="1.8*" java-vm-args="-Dawt.useSystemAAFontSettings=lcd"/>
2. In the env var JAVAWS_VM_ARGS

3. You can specify JVM args for a particular Jnlp file in the deployment.properties file. See https://openwebstart.com/docs/OWSGuide. ... _arguments

In both the cases specify this JVM argument in thejvm arg whitelist in the deployment.properties file for OWS to treat it as a secure argument:

Code: Select all

deployment.jvm.arguments.whitelist=-Dawt.useSystemAAFontSettings
Please see:https://openwebstart.com/docs/OWSGuide. ... _arguments

Candlejack
Posts: 2
Joined: 31 Mar 2026, 11:21

Re: Pass additional parameters to vm used by javaws

Post by Candlejack »

Thanks for the quick reply.

About option #2, using JAVAWS_VM_ARGS: As posted I tried setting them in my bashrc but the command line of the process did not show them. My assumption was that they should be visible if picked up, is that correct? Would I need to define them in some other place?

Janak Mulani
Posts: 1088
Joined: 24 Mar 2020, 13:37

Re: Pass additional parameters to vm used by javaws

Post by Janak Mulani »

In addition to the VM arguments specified in the JNLP file, you can provide additional arguments through the environment variable JAVAWS_VM_ARGS. If any argument you add is not included in the list of valid VM arguments recognized by OWS, it must first be added to the JVM argument whitelist in the deployment.properties file.

OWS enforces strict validation: if even a single VM argument cannot be validated, all VM arguments will be ignored. Any invalid arguments encountered are logged in the OWS Stage 1 log file.

Post Reply