Question

我试图在电子表格中迭代一组信息，我的电子表格有三列和两行。

这是我用来迭代信息的代码，

private List<DataRecord> allData = new ArrayList<>();

public DataRepository(String excelFilePath) {

    FileInputStream inputStream;
    try {
        inputStream = new FileInputStream(new File(excelFilePath));

        Workbook workbook = new XSSFWorkbook(inputStream);
        Sheet firstSheet = workbook.getSheetAt(0);
        Iterator<Row> iterator = firstSheet.iterator();

        while (iterator.hasNext()) {
            DataRecord record = new DataRecord();

            Row nextRow = iterator.next();
            Iterator<Cell> cellIterator = nextRow.cellIterator();
            while (cellIterator.hasNext()) {
                record.setCardNumber(cellIterator.next().getStringCellValue());
                record.setCvv(cellIterator.next().getStringCellValue());
                record.setPostcode(cellIterator.next().getStringCellValue());

            }

            allData.add(record);
        }

        inputStream.close();
    } catch (IOException e) {

        e.printStackTrace();
    }
}

public List<DataRecord> getAllData() {
    return allData;

}

public void setAllData(List<DataRecord> allData) {
    this.allData = allData;
}

这在今天早上起作用，现在它似乎抛出了上述异常，我不确定为什么。

由于

这是完整的堆栈跟踪

    Caused by: java.util.NoSuchElementException: null
at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1205)
at java.util.TreeMap$ValueIterator.next(TreeMap.java:1252)
at gov.uk.dwp.epayments.repository.DataRepository.<init>(DataRepository.java:43)
at gov.uk.dwp.epayments.service.PayService.<init>(PayService.java:11)
at gov.uk.dwp.epayments.controller.PaymentController.<init>(PaymentController.java:23)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147)
... 18 common frames omitted

Answer 1

这段代码做得不好，导致之前调用next（），以确定是否有下一个单元格

Iterator<Cell> cellIterator = nextRow.cellIterator();
while (cellIterator.hasNext()) {
    record.setCardNumber(cellIterator.next().getStringCellValue());
    record.setCvv(cellIterator.next().getStringCellValue());
    record.setPostcode(cellIterator.next().getStringCellValue());
}

如果它有下一个项目但是前进三次，您将检查一次。（下三个例子）

如果你每行只有树单元格，你可以用这种方式（它是许多可能的解决方案中唯一的一个）：

Iterator<Cell> cellIterator = nextRow.cellIterator();
if(cellIterator.hasNext(){
    record.setCardNumber(cellIterator.next().getStringCellValue());
}
if(cellIterator.hasNext(){
    record.setCvv(cellIterator.next().getStringCellValue());
}
if(cellIterator.hasNext(){
    record.setPostcode(cellIterator.next().getStringCellValue());
}

引起：java.util.NoSuchElementException - 在Java中使用迭代器？

1 个答案: