Network/Wired - How to retrive list of domain users name

Hi, I am trying to get list of users in domain. But I am unable to get all users name, I can get only logged in user name. I need this in my project. I am using java programing to develop in my project. I used the below code. Its correct or not. How can i get the all users name from system domain. Kindly any one help me.

Properties envVars = new Properties();
Runtime r = Runtime.getRuntime();
String OS = System.getProperty("os.name").toLowerCase();

if ((OS.indexOf("nt") > -1) || (OS.indexOf("windows 2000") > -1 ) || (OS.indexOf("windows xp") > -1) )
{
p = r.exec( "cmd.exe /c set" );
}

BufferedReader br = new BufferedReader ( new InputStreamReader( p.getInputStream() ) );
String line;
while( (line = br.readLine()) != null )
{
int idx = line.indexOf( '=' );
String key = line.substring( 0, idx );
String value = line.substring( idx+1 );
envVars.setProperty( key, value );
}


Regards
Palani