THIS IS THE PROGRAM WHICH WILL EXPLAIN ABOUT THE PROPERTIES CLASS IN JAVA.UTIL PACKAGE

import java.util.*;

public class Proper{

public static void main(String args[])

{

Properties p= System.getProperties();

p.list(System.out);

String course=System.getProperty("ramu");

System.out.println("NOW USER DEFINED PROPERTY IS STARTED");

if(course.equals("dayina@chirala"))

System.out.println(course);

else

System.out.println("UNKNOWN");

}

}

execution 

D:\Threads>java -Dramu=dayina@chirala Proper

-- listing properties --

PROPERTIENAME= VALUE

java.runtime.name=Java(TM) SE Runtime Environment

sun.boot.library.path=C:\Program Files\Java\jre1.8.0_31\bin

java.vm.version=25.31-b07

java.vm.vendor=Oracle Corporation

java.vendor.url=http://java.oracle.com/

path.separator=;

java.vm.name=Java HotSpot(TM) Client VM

file.encoding.pkg=sun.io

ramu=dayina@chirala

NOW USER DEFINED PROPERTY IS STARTED

dayina@chirala