NullPointerException for ubuntu 12.04

[GoogleCodeExporter]

hid_mgr = HIDManager.getInstance();
dev = hid_mgr.openById(VENDOR_ID, PRODUCT_ID,null );
System.out.println("Manufacturer: " + dev.getManufacturerString() + "\n"); 
System.out.println("Product: " + dev.getProductString() + "\n");
System.out.println("Serial Number: " + dev.getSerialNumberString() + "\n");

When i run System.out.println("Manufacturer: " + dev.getManufacturerString() + 
"\n") 
NullPointerException  .But this is No problem for Windows7 and Mac .Why?

Original issue reported on code.google.com by gooow...@gmail.com on 22 Sep 2013 at 3:09