Java Programming

hi,

i want to read system properties in my xml file using ${} .
I tried it but did not find any way.But when i use log4j if i set some variable in
System properties that properties is read by the log4j.properties .
I am writing a simple program that read a xml properties file file

try {
            props   = new Properties();
            fis     = new FileInputStream(xmlFile);
            props.loadFromXML(fis);
}

before reading this file i set some properties and accessing this properties from that xml .but i cant.


Thanks