Java-Selenium在指定的日期范围内查找表中的行

Question

在我的网站中，我可以选择一个日期范围并列出该日期范围内的所有内容。我的测试用例是验证列出的交易日期是否在所选日期范围内。

这是我的代码。我将所有交易日期保存到UI表中。 但是当我跑步时，我得到了You cannot call a method on a null-valued expression. At line:88 char:9 + $members = $this.super.retrieve.members() # !!! Problem exist ... + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (:) [], RuntimeException + FullyQualifiedErrorId : InvokeMethodOnNull 你能帮忙吗？这段代码有什么问题？

Unparseable date: "07/16/19"

customFormatter：

public boolean verifyTableDate(WebElement ElementTable, int columnNumber, String fromDate, String toDate){
    boolean result = true;
    String columnValue = "";

    WebElement disputeTableElem = null;
    List<WebElement> cellsTR;
    List<WebElement> cellsTD;
    int ctr;
    SimpleDateFormat fmt = new SimpleDateFormat("MM/dd/yy");
    SimpleDateFormat fmt1 = new SimpleDateFormat("MMM/dd/yyyy");
    Date parseFromDate;
    Date parseToDate;
    Date dateColumnVal;

    disputeTableElem = ElementTable;
    cellsTR = disputeTableElem.findElements(By.tagName("tr"));
    cellsTD = null;
    print("DATE RANGE: "+ fromDate + " - " + toDate);
    waitUntilPageLoadingIsComplete();
    for (WebElement cellTR : cellsTR) {
        cellsTD = cellTR.findElements(By.tagName("td"));
        ctr = 0;
        for (WebElement cellTD : cellsTD) {
            ctr++;
            if (ctr == columnNumber) {
                columnValue = cellTD.getText().trim().replaceAll("\n", " ");
                columnValue = columnValue.substring(0,8);
                try {
                    dateColumnVal = fmt.parse(columnValue);
                    parseFromDate = fmt1.parse(fromDate);
                    parseToDate = fmt1.parse(toDate);

                    String dateColumnValString = fmt.format(dateColumnVal);

                    if (dateColumnVal.compareTo(parseFromDate) >= 0 && dateColumnVal.compareTo(parseToDate) <= 0) {

                        print(dateColumnValString + " is within date range.");
                        highLightElement(cellTD);
                        result = true;
                    }else {
                        errorDesc += dateColumnValString + " is not within date range.";
                        result = false;
                    }
                } catch (ParseException e) {
                    e.printStackTrace();
                }

            }
        } 
    }
    return result;
} 

customFormatter1

DateTimeFormatter customFormatter = DateTimeFormatter.ofPattern("MMM/dd/YYYY");     
    String endDate = LocalDate.now(ZoneId.of(zoneID_EST)).format(customFormatter);
    String startDate = LocalDate.now(ZoneId.of(zoneID_EST)).minusDays(100).format(customFormatter);