I use this static method in one of my utility classes whenever I want to
display all the environment variables. You can adapt it to do what you want.
I'm using Java 1.5 but I'm pretty sure this should work in Java 1.4 if you
modify the line which instantiates the 'set' to this, i.e. delete the angle
brackets and what is within them:

       Set set = new TreeSet();

The code displays all of the properties in alphabetical order by key name.

---------------------------------------------------------------------------------------------------------------------
   static public void displaySystemProperties() {

       /*
        * Get a collection of all of the property names in the current JVM.
Use
        * a TreeSet so that the list of names will be in alphabetical
order.
        */
       Properties sysProps = System.getProperties();
       Set<String> set = new TreeSet<String>();
       for (Enumeration enum0 = sysProps.propertyNames();
enum0.hasMoreElements();) {
           set.add((String) enum0.nextElement());
       }

       /* Display each system property's key and value. */
       System.out.println("\n  System Properties: ");
       for (Iterator it = set.iterator(); it.hasNext();) {
           String key = (String) it.next(); //determine the key name
           /* Display the key name and its value. */
           System.out.println("    " + key + " = " +
sysProps.getProperty(key));
       }

       return;
   }

---------------------------------------------------------------------------------------------------------------------

--
Rhino

There isn't one.  That, after all, is why it was [re]added in 1.5 ;-)

The nearest you can easily get is to execute a system-dependent sub-process
which writes its environment to its stdout in a parsable form, which your Java
code then parses (remembering to take proper account of embedded newlines,
spaces, quotes, etc).  Of course, that depends on the environment of the parent
Java process being reproduced in the child.  Typically that will be the case --
more or less, and depending on the system, and on how you do it.

Alternatively, you could use JNI :-(

   -- chris

Benjamin Lerman schrieb:

The only way I see is to implement it in C and flange it to Java by JNI.

//the Java side:
  public class MySystem {
    public static native String getenv(String name);
  }

together with your C-implementation of the method above, where you call
the C-function getenv (as defined in <stdlib.h>).