Java - Apache POI - 读/写.xlsx文件 - 文件被破坏并变空

Question

我正在使用Java程序读取和写入现有的.xlsx文件(相同的文件),但文件已损坏,文件大小变为零字节,导致"org.apache.poi.EmptyFileException:提供的文件为空(零字节长)".

还有一件事 - 这种情况不会持续发生.该程序在大多数情况下正在读取和写入文件,但在10-15次运行中发生一次.如果有人有解决方案,那将会很有帮助.顺便说一句,我正在使用Apache POI 3.13.

阅读文件程序:

public String getExcelData(String sheetName, int rowNum, int colNum){
    String retVal = null;
    try {
        FileInputStream fis = new FileInputStream("/Absolute/File/Path/Test-File.xlsx");
        Workbook wb = WorkbookFactory.create(fis);
        Sheet s = wb.getSheet(sheetName);
        Row r = s.getRow(rowNum);
        Cell c = r.getCell(colNum);
        retVal=(c.getStringCellValue());
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (InvalidFormatException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return retVal;

写文件程序:

public void writeToExcel(String sheetName,int rowNum,int cellNum,String desc){
    try {
        FileInputStream fis = new FileInputStream("/Absolute/File/Path/Test-File.xlsx");
        Workbook wb = WorkbookFactory.create(fis);
        Sheet s = wb.getSheet(sheetName);
        Row r = s.getRow(rowNum);
        Cell c = r.createCell(cellNum);
        c.setCellValue(desc);
        FileOutputStream fos = new FileOutputStream("/Absolute/File/Path/Test-File.xlsx");
        wb.write(fos);
        fos.close();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (InvalidFormatException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

错误跟踪:

Exception in thread "main" org.apache.poi.EmptyFileException: The supplied file was empty (zero bytes long)
at org.apache.poi.util.IOUtils.peekFirst8Bytes(IOUtils.java:55)
at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:201)
at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:168)
at ExcelLibrary.getExcelData(ExcelLibrary.java:139)
at Driver.main(Driver.java:82)

Answer 1

当您写入文件时，您似乎没有使用flush. 此外，您的close代码应该在块中完成，finally以确保即使发生错误，流也会关闭。