Excel文件未使用Apache存储内部内存

Question

我使用apache.i创建Excel文件。我得到了像Permission denied一样的错误，但我在清单文件中添加了权限。

用我为pdf创建的类似方式，它是有效的。

我参考了这个教程：https://www.mkyong.com/java/apache-poi-reading-and-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代码如下：

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)

请提前在此case..Thanks中提供帮助。

Answer 1

我认为你需要询问运行时权限，因为从Android6.0( level 23)开始，用户在应用运行时授予应用权限，而不是在安装应用时授予权限。

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);
    }