文件输出流 FileNotFoundException

Question

I'm using java SE eclipse. As I know, When there are no file named by parameter FileOutputStream constructor create new file named by parameter. However, with proceeding I see that FileOutputStream make exception FileNotFoundException. I really don't know Why this exception needed. Anything wrong with my knowledge?

My code is following(make WorkBook and write into file. In this code, although there are no file "data.xlsx", FileOutpuStream make file "data.xlsx".

    public ExcelData() {
    try {
        fileIn = new FileInputStream("data.xlsx");
        try {
            wb = WorkbookFactory.create(fileIn);
            sheet1 = wb.getSheet(Constant.SHEET1_NAME);
            sheet2 = wb.getSheet(Constant.SHEET2_NAME);
        } catch (EncryptedDocumentException | InvalidFormatException | IOException e) {
            e.printStackTrace();
        } // if there is file, copy data into workbook
    } catch (FileNotFoundException e1) {
        initWb();
        try {
            fileOut = new FileOutputStream("data.xlsx");
            wb.write(fileOut);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } 

    } // if there is not file, create init workbook

} // ExcelData()

If anything weird, please let me know, thank you

Answer 1

It will throw a FileNotFoundException if the file doesn't exist and cannot be created ( doc ), but it will create it if it can. To be sure you probably should first test that the file exists before you create the FileOutputStream (and create with createNewFile() if it doesn't)

File yourFile = new File("score.txt");
yourFile.createNewFile();
FileOutputStream oFile = new FileOutputStream(yourFile, false); 

Answer from here: Java FileOutputStream Create File if not exists

Answer 2

There is another case, where new FileOutputStream("...") throws a FileNotFoundException , ie on Windows, when the file is existing, but file attribute hidden is set.

Here, there is no way out, but resetting the hidden attribute before opening the file stream, like

Files.setAttribute(yourFile.toPath(), "dos:hidden", false);