How to get Windows username in Java?

Lookup the system property "user.name".

String username = System.getProperty("user.name");

• System Properties
• System.getProperty

Demonstration: Main.java

public class Main {
   public static void main(String[] args) {
      System.out.println(System.getProperty("user.name"));
   }
}

Output:

c:\dev\src\misc>javac Main.java

c:\dev\src\misc>java Main
rgettman

c:\dev\src\misc>

Try:

String userName = System.getProperty("user.name");

or

String userName = new com.sun.security.auth.module.NTSystem().getName()

Two ways

1. System.getProperty("user.name");

2. System.getenv("USERNAME");

Both are good for any OS

NTSystem.getName() also returns SYSTEM when the app runs on a windows service. There is no means to get the username with NTSystem when the app is running on a windows service