Problem while running USB port detection

Question

Hi,
Im having the sample program of USB detection using java.
it didn't show any compile error but it is showing run time exception.
That is
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/lo
gging/LogFactory
at com.mcreations.usb.windows.JavaxUsb.<clinit>(JavaxUsb.java:65)
at com.mcreations.usb.windows.WindowsUsbServices.<init>(WindowsUsbServic
es.java:46)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstruct
orAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingC
onstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at java.lang.Class.newInstance0(Class.java:355)
at java.lang.Class.newInstance(Class.java:308)
at javax.usb.UsbHostManager.createUsbServices(Unknown Source)
at javax.usb.UsbHostManager.getUsbServices(Unknown Source)
at SampleUSBTest.<init>(SampleUSBTest.java:23)
at SampleUSBTest.main(SampleUSBTest.java:16)
The program is:
import javax.usb.*;
import javax.usb.event.*;
public class HotplugListener implements UsbServicesListener
public void usbDeviceAttached(UsbServicesEvent event)
UsbDevice device = event.getUsbDevice();
System.out.println(getDeviceInfo(device) + " was added to the bus.");
public void usbDeviceDetached(UsbServicesEvent event)
UsbDevice device = event.getUsbDevice();
System.out.println(getDeviceInfo(device) + " was removed from the bus.");
private static String getDeviceInfo(UsbDevice device)
try
String product = device.getProductString();
String serial = device.getSerialNumberString();
if (product == null) return "Unknown USB device";
if (serial != null) return product + " " + serial;
else return product;
catch (Exception ex)
return "Unknown USB device";
pls help me to run this progam.
Thanks and Regards,
Selvi
Edited by: TamilSelviSubramani on Mar 11, 2008 8:54 AM

Answer 1

hi,
I added the commons-logging-1.1.jar file in classpath.But now itself it shows another run time Exception
That is,
javax.usb.UsbException: Error while loading shared library LibusbJNI.dll : no Li
busbJNI in java.library.path
at com.mcreations.usb.windows.JavaxUsb.loadLibrary(JavaxUsb.java:400)
at com.mcreations.usb.windows.JavaxUsb.initialise(JavaxUsb.java:329)
at com.mcreations.usb.windows.WindowsUsbServices.<init>(WindowsUsbServic
es.java:46)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstruct
orAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingC
onstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at java.lang.Class.newInstance0(Class.java:355)
at java.lang.Class.newInstance(Class.java:308)
at javax.usb.UsbHostManager.createUsbServices(Unknown Source)
at javax.usb.UsbHostManager.getUsbServices(Unknown Source)
at SampleUSBTest.<init>(SampleUSBTest.java:23)
at SampleUSBTest.main(SampleUSBTest.java:16)
Thanks and Regards,
Selvi