//
// program to display and set System properties.
//

import java.util.Properties ;
import java.util.Enumeration ;

public class ShowSystemProps {

        public static void main(String[] args) {

                // get Properties table containing system properties
                Properties sysProps = System.getProperties() ;

                // get enumeration object to look at all elements
                Enumeration e = sysProps.propertyNames() ;

                // print names and values of all system properties
                System.out.println("List of all system properties:") ;
                System.out.println() ;
                while (e.hasMoreElements()) {
                                        // note typecast
                        String pName = (String) e.nextElement() ;
                        String pValue = sysProps.getProperty(pName) ;
                        System.out.println("Property name:  " + pName) ;
                        System.out.println("\tProperty value:  " + pValue) ;
                }

                // add a couple of new properties
                sysProps.put("myProps.helloWorld", "Hello, world!") ;
                sysProps.put("myProps.helloWeb", "Hello, Web!") ;

                // save resulting Properties object as system
                //      properties
                System.setProperties(sysProps) ;

                // display some system properties, including the
                //      newly-added ones (note that we don't need
                //      an enumerator if we already know the name
                //      of the property we want)
                System.out.println() ;
                System.out.println("Values for selected system " +
                        "properties, including some we added:") ;
                System.out.println() ;
                String temp ;
                temp = System.getProperty("java.version") ;
                System.out.println("Value for java.version = " 
                        + temp) ;
                temp = System.getProperty("user.timezone") ;
                System.out.println("Value for user.timezone = " 
                        + temp) ;
                temp = System.getProperty("myProps.helloWorld") ;
                System.out.println("Value for myProps.helloWorld = " 
                        + temp) ;
                temp = System.getProperty("myProps.helloWeb") ;
                System.out.println("Value for myProps.helloWeb = " 
                        + temp) ;
        }
}