How to pass a system property using Wrapper.exe

http://wrapper.tanukisoftware.org/doc/english/prop-java-additional-n.html

You can set "additional parameters" that will go to the JVM (as opposed to your main class), and -DADMIN_USERNAME=gandalf should work there.

wrapper.java.additional.1=-Xrs
wrapper.java.additional.2=-Dprop=TRUE
wrapper.java.additional.3=-DADMIN_USERNAME=gandalf

Update: You must start with additional.1 and count up without gaps (This is a convention for shoe-horning lists into Java properties syntax).