Excel文件不是使用Apache存储内部内存

Question

i使用apache创建excel文件。我在 Permission denied中获得错误，但我在清单文件中添加了权限。

以类似的方式为PDF创建它。

我推荐了本教程：https：//www.mkyong.com/java/apache-poi-reading-and-writing-writing-writing-writing-excel-file-in-java/

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

我的Java代码下面：

buttonone.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                createfile();
            }
        });
private void createfile()
    {
        XSSFWorkbook workbook = new XSSFWorkbook();
        XSSFSheet sheet = workbook.createSheet("Datatypes in Java");
        Object[][] datatypes = {
                {"Datatype", "Type", "Size(in bytes)"},
                {"int", "Primitive", 2},
                {"float", "Primitive", 4},
                {"double", "Primitive", 8},
                {"char", "Primitive", 1},
                {"String", "Non-Primitive", "No fixed size"}
        };
        int rowNum = 0;
        System.out.println("Creating excel");
        for (Object[] datatype : datatypes) {
            Row row = sheet.createRow(rowNum++);
            int colNum = 0;
            for (Object field : datatype) {
                Cell cell = row.createCell(colNum++);
                if (field instanceof String) {
                    cell.setCellValue((String) field);
                } else if (field instanceof Integer) {
                    cell.setCellValue((Integer) field);
                }
            }
        }
        try {
            String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/IDEA FILES/"+"MyFirstExcel.xlsx";
            File dir = new File(path);
            if (!dir.exists())
                dir.mkdirs();
            FileOutputStream fOut = new FileOutputStream(dir);
            workbook.write(fOut);
            fOut.flush();
            fOut.close();
            workbook.close();
            //viewExecel()
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            Log.d("getpermission","**   "+e.toString());
        } catch (IOException e) {
            e.printStackTrace();
            Log.d("getpermission","**ioexeption   "+e.toString());
        }
        System.out.println("Done");

    }

运行时间错误：

09-20 11:38:36.544 20869-20869/pro.kondratev.xlsxpoiexample W/System.err: java.io.FileNotFoundException: /storage/emulated/0/IDEA FILES/MyFirstExcel.xlsx: open failed: EACCES (Permission denied)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:452)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:87)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at java.io.FileOutputStream.<init>(FileOutputStream.java:72)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at pro.kondratev.xlsxpoiexample.MainActivity.createfile(MainActivity.java:93)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at pro.kondratev.xlsxpoiexample.MainActivity.access$000(MainActivity.java:33)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at pro.kondratev.xlsxpoiexample.MainActivity$1.onClick(MainActivity.java:52)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at android.view.View.performClick(View.java:5201)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at android.view.View$PerformClick.run(View.java:21163)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at android.os.Handler.handleCallback(Handler.java:746)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:95)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at android.os.Looper.loop(Looper.java:148)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5443)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
09-20 11:38:36.553 20869-20869/pro.kondratev.xlsxpoiexample W/System.err: Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)
09-20 11:38:36.555 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at libcore.io.Posix.open(Native Method)
09-20 11:38:36.555 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
09-20 11:38:36.555 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:     at libcore.io.IoBridge.open(IoBridge.java:438)
09-20 11:38:36.556 20869-20869/pro.kondratev.xlsxpoiexample W/System.err:   ... 14 more
09-20 11:38:36.556 20869-20869/pro.kondratev.xlsxpoiexample D/getpermission: **   java.io.FileNotFoundException: /storage/emulated/0/IDEA FILES/MyFirstExcel.xlsx: open failed: EACCES (Permission denied)

请在这种情况下提供帮助。

我认为您需要问运行时间permssion从Android 6.0开始（API级别23），用户在运行应用程序时授予应用程序的权限，而不是安装应用程序时。

代码

String permission = Manifest.permission.WRITE_INTERNAL_STORAGE;
int grant = ContextCompat.checkSelfPermission(this, permission);
    if (grant != PackageManager.PERMISSION_GRANTED) {
         String[] permission_list = new String[1];
         permission_list[0] = permission;
         ActivityCompat.requestPermissions(this, permission_list, 1);
    }