Apache POI throwing null pointer exception

Question

I am running the scheduler a cron job scheduler, which is running sql query on server and generate a report in excel format, for first time cron job is working fine when job trigger next it throws null pointer exception.

@Component
public class ToleranceReport {

    Email email = new Email(); 

    private static final Logger LOGGER = LoggerFactory.getLogger(ToleranceReport.class);

    private String path = Constants.PATH + "Tolerance_Alert_Report.xlsx";
    SXSSFWorkbook xlsxWorkbook5 = new SXSSFWorkbook();
    SXSSFSheet xlsSheet5 = xlsxWorkbook5.createSheet();
    int rowIndex5 = 1;

@Scheduled(cron = "30 40 8 * 1-12 4,5,6")
    public void tolerance_Generator() throws IOException, SQLException, ClassNotFoundException, MessagingException {

        File Tolerancefile = ResourceUtils.getFile("classpath:GE_Files/ToleranceReport/R1.txt");

        String TolerancefirstPart = new String(Files.readAllBytes(Tolerancefile.toPath()));
//      System.out.println(TolerancefirstPart);

        try {
            LOGGER.info("Starting Tolerance Report");
            Class.forName("oracle.jdbc.driver.OracleDriver");
            // step2 create the connection object
            Connection con5 = DriverManager.getConnection(
                    "*****", "****", "*****");
            {
                LOGGER.info("Connected");
                Statement stmt5 = con5.createStatement();
                LOGGER.info("Executing");
                // step4 execute query

                ResultSet rs5 = stmt5.executeQuery(TolerancefirstPart);
                ResultSetMetaData colInfo5 = rs5.getMetaData();
                ArrayList<String> colNames5 = new ArrayList<>();
                SXSSFRow titleRow5 = xlsSheet5.createRow(rowIndex5++);

                for (int i = 1; i <= colInfo5.getColumnCount(); i++) {
                    colNames5.add(colInfo5.getColumnName(i));
                    titleRow5.createCell((int) (i - 1)).setCellValue(new XSSFRichTextString(colInfo5.getColumnName(i)));
                    xlsSheet5.setColumnWidth((int) (i - 1), (int) 16000);
                }
                while (rs5.next()) {
                    SXSSFRow dataRow5 = xlsSheet5.createRow(rowIndex5++);
                    int colIndex5 = 0;
                    for (String colName5 : colNames5) {
                        dataRow5.createCell(colIndex5++).setCellValue(new XSSFRichTextString(rs5.getString(colName5)));
                    }
                }
                FileOutputStream fo = new FileOutputStream(path);
                xlsxWorkbook5.write(fo);
                LOGGER.info("Exported Successfully");
                rs5.close();
                stmt5.close();
                fo.close();
                con5.close();
                xlsxWorkbook5.close();
                LOGGER.info("Closed");
            }
            email.sendMail(path, Constants.TOLERANCE_TO, Constants.CC, Constants.TOLERANCE_SUBJECT, Constants.EMAIL_CONTENT);
            FileDelete.deletefileData(path);
        } catch (IOException | SQLException | ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
        }
    }
}

Error on this error this line SXSSFRow titleRow5 = xlsSheet5.createRow(rowIndex5++);

java.lang.NullPointerException
    at com.ge.report.reports1st.FoodWaste.foodWaste(FoodWaste.java:313)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84)
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
    at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:93)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

Could you please look into this and let me know why it is throwing, once it ran without any issues