Question

for循环的目的是为文件中的每一行文本创建一个新的currentJob并将其存储在一个数组中。循环存储第一行文本，但不存储任何其他内容。

public static void job()
{
    File file = new File("DailyJobs.txt");

    try
    {
        Scanner scanner = new Scanner(file);
        while(scanner.hasNextLine())
        {
            String line = scanner.nextLine();
            Scanner lineScanner = new Scanner(line);
            lineScanner.useDelimiter(",");

            Job[] jobArray = new Job[30];

            for (int i = 0; i < jobArray.length; i++)
            {
                Job currentJob = new Job();

                int jID = lineScanner.nextInt();
                int cID = lineScanner.nextInt();
                String rego = lineScanner.next();
                String date = lineScanner.next();
                String day = lineScanner.next();
                double fee = lineScanner.nextDouble();

                int[] sc = new int[4];
                int f = 0;
                while(lineScanner.hasNextInt())
                {
                    lineScanner.useDelimiter(",");
                    sc[f] = (lineScanner.nextInt());
                    f++;
                }

                currentJob.setJobID(jID);
                currentJob.setCustomerID(cID);
                currentJob.setRegistration(rego);
                currentJob.setDate(date);
                currentJob.setDay(day);
                currentJob.setTotalFee(fee);
                currentJob.setServiceCode(sc);

                jobArray[i] = currentJob;


                System.out.println(currentJob.getJobID());
                System.out.println(currentJob.getCustomerID());
                System.out.println(currentJob.getRegistration());
                System.out.println(currentJob.getDate());
                System.out.println(currentJob.getDay());
                System.out.println(currentJob.getTotalFee());
                System.out.println(Arrays.toString(currentJob.getServiceCode()));

                System.out.println(Arrays.toString(jobArray));



            }


        }
    }catch (Exception e)
    {

    }
}
}

`` 这就是我现在所得到的

90301
14304
ITGURU
11/11/2014
Tuesday
735.75
[1204, 1205, 0, 0]
[Job@1c31e2ad, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null]

90301下至[1204,1205,0,0]是该行的内容。你可以看到它存储文本文件的第一行，然后什么也没有。我需要帮助来解决这个问题。

完全忘记了catch语句是空的但是它显示了一些问题

java.util.NoSuchElementException
    at java.util.Scanner.throwFor(Scanner.java:907)
    at java.util.Scanner.next(Scanner.java:1530)
    at java.util.Scanner.nextInt(Scanner.java:2160)
    at java.util.Scanner.nextInt(Scanner.java:2119)
    at test3.job(test3.java:31)
    at test3.main(test3.java:9)

以上是我得到的。

DailyJobs.txt

90301,14304,ITGURU,11/11/2014,Tuesday,735.75,1204,1205
90302,14314,ROK5TR,12/11/2014,Wednesday,335.75,1205
90303,14318,HRTBRK,13/11/2014,Thursday,125.5,1200
90304,14310,EVOH8R,14/11/2014,Friday,1207.95,1211
90305,14300,G4MER,11/11/2014,Tuesday,500,1204,1202
90306,14312,COFFEE,11/11/2014,Tuesday,100,1202
90307,14316,POPULR,11/11/2014,Tuesday,150,1203
90308,14317,WRXSTI,11/11/2014,Tuesday,1307.95,1211,1202
90309,14321,FAST,11/11/2014,Tuesday,400,1204
90310,14308,PRQUL8,14/11/2014,Friday,150,1203
90311,14315,OK2BL8,14/11/2014,Friday,335.75,1205
90312,14320,OLDGUY,11/11/2014,Tuesday,1207.95,1211
90313,14313,ABC123,12/11/2014,Wednesday,,1202,1203,1205,1210
90314,14306,WAIT,11/11/2014,Tuesday,150,1203
90315,14302,FUZZ,14/11/2014,Friday,335.75,1205
90316,14313,GO,12/11/2014,Wednesday,,1204,1202
90317,14309,SING,13/11/2014,Thursday,400,1204
90318,14307,MANIC,12/11/2014,Wednesday,100,1202
90319,14305,URABUS,14/11/2014,Friday,1207.95,1211
90320,14303,STOP,14/11/2014,Friday,150,1203
90321,14310,BAKOFF,11/11/2014,Tuesday,,1204,1205
90322,14322,WINNER,14/11/2014,Friday,1207.95,1211
90323,14324,KITTY,13/11/2014,Thursday,400,1204
90324,14325,WEDDIN,12/11/2014,Wednesday,100,1202
90325,14326,FIGHTR,11/11/2014,Tuesday,100,1202
90326,14320,OLDGUY,14/11/2014,Friday,175.9,1208
90327,14322,QUICK,12/11/2014,Wednesday,,1203,1204,1209
90328,14322,L8R,13/11/2014,Thursday,400,1204
90329,14299,TRUTH,13/11/2014,Thursday,80.25,1197
90330,14337,NIGHT,13/11/2014,Thursday,150,1203
90331,14312,COFFEE,13/11/2014,Thursday,350,1204

Answer 1

你应该把

        String line = scanner.nextLine();
        Scanner lineScanner = new Scanner(line);
        lineScanner.useDelimiter(",");

在你的for循环中

。

Answer 2

您提到此处发生异常NoSuchElementException：

int jID = lineScanner.nextInt();

这意味着，扫描程序会尝试读取不存在的int。主要问题是您当前的代码结构：

int jID = lineScanner.nextInt();
int cID = lineScanner.nextInt();
String rego = lineScanner.next();
String date = lineScanner.next();
String day = lineScanner.next();
double fee = lineScanner.nextDouble();

// omitted code
while(lineScanner.hasNextInt())
{
    lineScanner.useDelimiter(",");
    sc[f] = (lineScanner.nextInt());
    f++;
}

您正在阅读一些内容并将其分配给变量，然后您将一直读到最后一个整数（lineScanner.hasNextInt()）。如果没有可读的整数可用，则此循环将停止。在那之后，你在做更多不需要的东西。

这是for (int i = 0; i < jobArray.length; i++)的第一次迭代。现在是下一次迭代。 lineScanner仍然相同，因此由于循环while(lineScanner.hasNextInt())而有读取整数，但第二次迭代将到达行int jID = lineScanner.nextInt();。扫描程序尝试读取int，找不到要读取的内容并抛出NoSuchElementException。

要解决此问题，您应重置lineScanner以阅读新行。或者删除for循环，因为while(scanner.hasNextLine())将负责阅读每个可用行，并且lineScanner将正确填充。请重新考虑变量Job[] jobArray = new Job[30];的当前位置。您将丢失文件每个新行的数据。

for循环填充数组[0]但就是这样

2 个答案: