Get login username in java

Question

How can I get the username/login name in Java?

This is the code I have tried...

try{     LoginContext lc = new LoginContext(appName,new TextCallbackHandler());     lc.login();     Subject subject = lc.getSubject();     Principal principals[] = (Principal[])subject.getPrincipals().toArray(new Principal[0]);      for (int i=0; i<principals.length; i++) {         if (principals[i] instanceof NTUserPrincipal || principals[i] instanceof UnixPrincipal) {             String loggedInUserName = principals[i].getName();         }     }  } catch(SecurityException se){     System.out.println("SecurityException: " + se.getMessage()); } 

I get a SecurityException when I try to run this code. Could someone please tell me whether I'm heading in the right direction, and help me to understand the problem.

Answer 1

System.getProperty("user.name"); 

Answer 2

in Unix:

new com.sun.security.auth.module.UnixSystem().getUsername() 

in Windows:

new com.sun.security.auth.module.NTSystem().getName() 

in Solaris:

new com.sun.security.auth.module.SolarisSystem().getUsername()