Someone

private synchronized void addData(int Col, int Row, String data) throws IOException{
        System.out.println("Data saved - Column: "+Col+" Row: "+Row+" Data: "+data);
        HSSFRow row = sheet1.createRow((short) Row);
        HSSFCell entrycell = row.createCell((short) Col);
        entrycell.setCellValue(data);
        wb.write(fileOut);
    }