JAVA - Hashtable, how to read java system properties

In java.lang.System class are accessible system properties. Data are saved internally in java.util.Hashtable class.

This sample code go through Hashtable and read all its keys and values.

import java.util.*;
...
/* -- get system properties */

Hashtable h = System.getProperties();

/* -- get keys */

Enumeration e = h.keys();

/* -- read and write all keys */

while( e.hasMoreElements() ) {

  /* key */
  Object k = e.nextElement();

  /* read key */
  System.out.print( k );
  /* read key value */
  System.out.println( "\t\t" + h.get( k ) );
}

The output could be (depending on installed JDK and current system):

java.runtime.name Java(TM) SE Runtime Environment
sun.boot.library.path C:\Program Files\Java\jdk1.7.0_07\jre\bin
java.vm.version 23.3-b01
java.vm.vendor Oracle Corporation
java.vendor.url http://java.oracle.com/
path.separator ;
java.vm.name Java HotSpot(TM) Client VM
...