I have properties file in local to which I am reading in code by below method String pathOfFile = System.getProperties("arg.get.prop");
How to set this system properties to get my property file's path in liberty server.xml
If you need to define system property the recommended way is to use jvm.options file and put your property there like:
# Set a system property.
-Darg.get.prop=ExampleValue
you may need to create that file in the ${server.config.dir} directory. For some more details check Customizing the Liberty environment