Android 10及以上设备未创建文件或目录

Question

我正在开发一个多文件转换器应用程序，用户可以在其中将 select 一个 excel 文件转换为 pdf，下面的方法用于创建 pdf 文件，该文件在我的手机中运行良好，即 android 派（android 9），但是当我在 android 中运行应用程序 10 真实设备也在模拟器中没有创建目录。 请帮助我处理代码并使用 dexter 库请求运行时许可

我在清单中添加了这一行：-

  android:requestLegacyExternalStorage="true"

权限：--

  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

我的 CreatePDF 方法：-

 void Convert_to_PDF(Uri path) throws IOException, DocumentException, URISyntaxException {

   File f = new File(Environment.getExternalStorageDirectory() + "/MultiFileCon");



    if (!f.exists()) if ( !f.mkdir()) return;




    SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HH.mm.ss");
    Date date = new Date();
    // System.out.println(formatter.format(date));
    Log.d("DATE", formatter.format(date) + ".pdf");

    File pdffilex = new File(f.getAbsolutePath(), formatter.format(date) + ".pdf");


    Log.d("ABC", "Convert_to_PDF: "+uriforExcel.getPath());


    if (android.os.Build.VERSION.SDK_INT > Build.VERSION_CODES.P) {
        Toast.makeText(this, "android version is "+android.os.Build.VERSION.SDK_INT, Toast.LENGTH_LONG).show();
        Log.d("VERSION NAME", "Convert_to_PDF: "+android.os.Build.VERSION.SDK_INT);
        File file = new File(path.getPath());//create path from uri
        final String[] split = file.getPath().split(":");//split the path.
       filePath = split[1];
        input_document = new FileInputStream(filePath);
    }
    else {
        input_document = new FileInputStream(new File(PathUtil.getPath(this,path)));
    }




    // Read workbook into HSSFWorkbook
    HSSFWorkbook my_xls_workbook = new HSSFWorkbook(input_document);




    // Read worksheet into HSSFSheet
    HSSFSheet my_worksheet = my_xls_workbook.getSheetAt(0);
    // To iterate over the rows
    Iterator<Row> rowIterator = my_worksheet.iterator();
    //We will create output PDF document objects at this point
    Document iText_xls_2_pdf = new Document();
    PdfWriter.getInstance(iText_xls_2_pdf, new FileOutputStream(pdffilex));
    iText_xls_2_pdf.open();
    //we have two columns in the Excel sheet, so we create a PDF table with two columns
    //Note: There are ways to make this dynamic in nature, if you want to.
    PdfPTable my_table = new PdfPTable(7);
    //We will use the object below to dynamically add new data to the table
    PdfPCell table_cell;
    //Loop through rows.
    while(rowIterator.hasNext()) {
        Row row = rowIterator.next();
        Iterator<Cell> cellIterator = row.cellIterator();
        while(cellIterator.hasNext()) {
            Cell cell = cellIterator.next(); //Fetch CELL
            switch(cell.getCellType()) { //Identify CELL type
                //you need to add more code here based on
                //your requirement / transformations
                case Cell.CELL_TYPE_STRING:
                    //Push the data from Excel to PDF Cell
                    table_cell=new PdfPCell(new Phrase(cell.getStringCellValue()));
                    Log.d("DOL", cell.getStringCellValue());






                    //feel free to move the code below to suit to your needs
                    my_table.addCell(table_cell);
                    break;
            }
            //next line
        }

        // Log.d("DOL", "Convert_to_PDF: "+datatobe);

    }
    //Finally add the table to PDF document
    iText_xls_2_pdf.add(my_table);
    iText_xls_2_pdf.close();
    //we created our pdf file..
    input_document.close(); //close xls
}

Answer 1

SimpleDateFormat 格式化程序 = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");

':'

是文件系统路径中的禁止字符。

尝试：。

 "dd-MM-yyyy HH.mm.ss"

Answer 2

出于安全原因， Environment.getExternalStorageDirectory()方法不适用于 Android 11 或更高版本的设备。

您可以轻松地将文件存储在公共目录中。 以下是您如何访问 Android Studio 中的公共目录的示例。

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);

所以你可以在你的项目中尝试这段代码。

File baseFile = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), "MultiFileCon");

if (!baseFile.exists()) {
    baseFile.mkdirs();
}

File pdfFile = new File(baseFile, "PDF_" + Calendar.getInstance().getTimeInMillis() + ".pdf");

Log.e(TAG, "onCreate: pdfFile path is:  " + pdfFile.getAbsolutePath());

• 在这里你得到的路径是这样的： /storage/emulated/0/Download/MultiFileCon/PDF_1665148985587.pdf