Getting Null pointer exception when trying to read the xlsx

Hi 

I am getting a null pointer exception in this code. Followed all the steps in module 6

1. copied the readfiles.jar in the library

2.Copied all the poi jar files in the library

3. Stored the xlsx in the mentioned path.

import com.soapuitutorial.property.Xls_Reader

def path="C:\\Tools\\soapui\\Data.xlsx"

Xls_Reader xls = new Xls_Reader(path)
// count rows
//log.info "Total rows " +
//log.info xls.getRowCount("LoginTest")
// count cols
//log.info "Total cols " + xls.getColumnCount("LoginTest")