Workstation

Host Name and Address

try {
    java.net.InetAddress i = java.net.InetAddress.getLocalHost();
    System.out.println(i);                  // name and IP address
    System.out.println(i.getHostName());    // name
    System.out.println(i.getHostAddress()); // IP address only
} catch (Exception e) {
    e.printStackTrace();
}

User Name

System.getProperty("user.name")

For a list of properties.

Windows

See Tips for the location of java.exe and javaw.exe.