Question

有人可以告诉我以下代码有什么问题吗？我试图对存储在“Options”变量中的数组进行排序。但它抛出'Null'例外。

public static void CheckOptionsPresent(String s1) throws Exception
{
    try
    {
        List optionsList=null;     
        webDriver.findElement(By.cssSelector("article.ContactInfo.active div.half-left.contactInfo div.idProvinceOfIssuance button")).click();
        int listcount = webDriver.findElements(By.cssSelector("article.ContactInfo.active div.half-left.contactInfo div.idProvinceOfIssuance div ul li")).size();
        System.out.println(listcount);
        String[] options=new String[listcount];

        for (int i=2; i<=listcount; i++ )
        {
            options[i-1] = webDriver.findElement(By.cssSelector("article.ContactInfo.active div.half-left.contactInfo div.idProvinceOfIssuance div ul li:nth-child("+i+") a span")).getText();
            System.out.println(options[i-1]);
        }

        System.out.println(options.length);

        for(int j=0; j<options.length;j++)
        {
            for (int i=j+1 ; i<options.length; i++)
            {
                if(options[i].compareToIgnoreCase(options[j])<0)
                {
                String temp= options[j];
                options[j]= options[i]; 
                options[i]=temp;


                }
            }

            System.out.println(options[j]);
        }
    }
    catch (RuntimeException e) 
    {
        System.out.println(e.getMessage());
        throw new RuntimeException(e.getMessage());
    }
}

输出

14
AB - Alberta
BC - British Columbia
MB - Manitoba
NB - New Brunswick
NL - Newfoundland and Labrador
NS - Nova Scotia
NT - Northwest Territories
NU - Nunavut
ON - Ontario
PE - Prince Edward Island
QC - Québec
SK - Saskatchewan
YT - Yukon Territory
14

以下是错误：

org.eclipse.debug.core.DebugException: com.sun.jdi.ClassNotLoadedException: Type has not been loaded occurred while retrieving component type of array.

for (int i=j+1 ; i<options.length; i++) {
    if(options[i].compareToIgnoreCase(options[j])<0) {
        String temp= options[j]; options[j]= options[i];
        options[i]=temp; 
    } 
}

Answer 1

String.compareToIgnoreCase()不喜欢null作为其论点。

第一次循环后，options[0] = null;

NullPointerException在第一次传递if(options[i].compareToIgnoreCase(options[j])<0)时被点击，然后索引为(i = 1, j = 0)，就会发生var array = new List<object>(); var offers = new List<object>(); offers.Add(new { ItemName = itnme, Price = price, Quantity = quant, }); array.Add(new { Dealname = dealname, Ticketcount = tictnum, OriginalPrice = origpri, Dealsticketcount = dealsticktnu, dealprice = dp, totalprice = totamnt, Offers = offers });。

Answer 2

工作代码：

public static void CheckOptionsPresent(String s1) throws Exception {
    try {
        List < String > optionsList = null;
        webDriver.findElement(By.cssSelector("article.ContactInfo.active div.half-left.contactInfo div.idProvinceOfIssuance button")).click();
        int listcount = webDriver.findElements(By.cssSelector("article.ContactInfo.active div.half-left.contactInfo div.idProvinceOfIssuance div ul li")).size();
        System.out.println(listcount);
        String[] options = new String[listcount];

        for (int i = listcount; i >= 2; i--) {
            options[i - 1] = webDriver.findElement(By.cssSelector("article.ContactInfo.active div.half-left.contactInfo div.idProvinceOfIssuance div ul li:nth-child(" + i + ") a span")).getText();
            System.out.println(options[i - 1]);
            optionsList = Arrays.asList(options);

        }
        System.out.println(optionsList);
        System.out.println(isSorted(optionsList));

    } catch (RuntimeException e) {
        System.out.println(e.getMessage());
        throw new RuntimeException(e.getMessage());
    }
}
public static boolean isSorted(List < String > list) {
    boolean sorted = true;
    for (int i = 0; i < list.size() - 1; i++) {
        if (list.get(i) == null) continue;
        if (list.get(i).compareTo(list.get(i + 1)) > 0) sorted = false;
    }

    return sorted;
}

排序数组不起作用

2 个答案: