java - File Excel From Apache POI Cant Open by Ms Excel (corrupt)

Question

I don't know why the file I write using POI cant be opened by Ms Excel 2013, but the file is still readable by POI. (cell value can be changed)

this is the error from file

here is the code

FileInputStream fis = null;
    try {
        fis = new FileInputStream(fileUri); //not error at fileUri
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    String urii = fileUri.replace(".xls", "0.xls"); //not error
    File fisx = new File(urii);

    Workbook workbook = null;
        workbook = new HSSFWorkbook(fis);

    Sheet sheet = workbook.getSheetAt(0);

    Row row = sheet.getRow(0);

    Cell cell = row.getCell(0);

    String p = cell.getStringCellValue();

    TextView a = (TextView) findViewById(R.id.txtUri);

    cell.setCellValue(new String("popo"));
    String x = cell.getStringCellValue();

    TextView b = (TextView) findViewById(R.id.txtFile);

    a.setText(p);
    b.setText(x);

    OutputStream fos = null;

    fos = new FileOutputStream(fisx);
    workbook.write(fos); //main problem
    fos.flush();
    fos.close();

Thanks for your help!!

Answer 1

There are two issues with your code. Firstly this:

FileInputStream fis = null;
try {
    fis = new FileInputStream(fileUri);

As explained in the Apache POI Docs, don't use an InputStream if you have a File!

Secondly, this:

 Workbook workbook = null;
 workbook = new HSSFWorkbook(fis);

That will only work for .xls files, not for .xlsx ones. Instead, you need to use WorkbookFactory which identifies the type and gives you the right workbook for the format

So, change your code to be

File file = new File(fileUri);
Workbook workbook = WorkbookFactory.create(file);