The getProperty method in the System class can be used to display the system properties defined for your environment. Here is an utility program which takes the property name as the command line argument and prints out its value on the stdout.
class ShowSysProp{ public static void main(String[] args) { // Take care of the cmd line args checks String progArg = args[0]; System.out.println(progArg+":"+System.getProperty(progArg)); }}