import java.util.*;
import javax.usb.*;
public class USBLister {
  public static void main(String[] args) throws UsbException {
    UsbServices services = UsbHostManager.getUsbServices( );
    UsbHub root = services.getRootUsbHub( );
    listDevices(root);
  }
  public static void listDevices(UsbHub hub) {
    List devices = hub.getAttachedUsbDevices( );
    Iterator iterator = devices.iterator( );
    while (iterator.hasNext( )) {
      UsbDevice device = (UsbDevice) iterator.next( );
      System.out.println(device);
      if (device.isUsbHub( )) {
        listDevices((UsbHub) device);
      }
    }
  }
}