Java - Apache POI - Convert XLS/XLSX to CSV

ExcelReading.java

/*
 * Dependencies: Apache POI Library from http://poi.apache.org/
 */
package poi_excels;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;

/**
 *
 * @author Munawwar
 */
public class ExcelReading {

    public static void echoAsCSV(Sheet sheet) {
        Row row = null;
        for (int i = 0; i < sheet.getLastRowNum(); i++) {
            row = sheet.getRow(i);
            for (int j = 0; j < row.getLastCellNum(); j++) {
                System.out.print("\"" + row.getCell(j) + "\";");
            }
            System.out.println();
        }
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        InputStream inp = null;
        try {
            inp = new FileInputStream("myxlsx/sample.xlsx");
            Workbook wb = WorkbookFactory.create(inp);

            for(int i=0;i<wb.getNumberOfSheets();i++) {
                System.out.println(wb.getSheetAt(i).getSheetName());
                echoAsCSV(wb.getSheetAt(i));
            }
        } catch (InvalidFormatException ex) {
            Logger.getLogger(ExcelReading.class.getName()).log(Level.SEVERE, null, ex);
        } catch (FileNotFoundException ex) {
            Logger.getLogger(ExcelReading.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(ExcelReading.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            try {
                inp.close();
            } catch (IOException ex) {
                Logger.getLogger(ExcelReading.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
}

ExcelReading.class.getName() getting error.what is the case?