/ storage / emulated / 0 / android.system.ErrnoException: открыть не удалось: EACCES (В доступе отказано)

Question

Я обнаружил запутанную проблему с функцией автоматической загрузки новой версии приложения

1.основной код раздела деятельности:

    private void downloadFile(String url)  {


       String dir =  FileUtils.getSDCardPath()+ "/";

        String fileName = System.currentTimeMillis() + ".apk";

        path=dir+fileName;

        verifyStoragePermissions(UpdateActivity.this);
        if (shouldAskPermissions()) {
            askPermissions();
        }

        OkHttpUtils
                .get()
                .url(url)
                .build().execute(
                new FileCallBack(dir,fileName) {

                    @Override
                    public void onBefore(Request request, int id) {
                        super.onBefore(request, id);



                    }

                    @Override
                    public void inProgress(float progress, long total, int id) {
                       // super.inProgress(progress, total, id);
                        int progressl=(int) (100 * progress);
                        L.i("toal "+total);
                        L.i("prgress :"+progressl);

                        Message msg=new Message();
                        msg.what=HANDLER_LODING;

                        Bundle bundle=new Bundle();
                        bundle.putLong("total",total);
                        bundle.putInt("progress",progressl);
                        msg.setData(bundle);
                        handler.sendMessage(msg);

                    }

                    @Override
                    public void onError(Call call, Exception e, int id) {

                        L.i("error" +e.getMessage().toString()+" local:"+e.getLocalizedMessage()+" cause "+e.getCause()+" code"+e.getStackTrace());
                        UtilTools.sendEmail(getClass().toString()+"失败 e:"+e.getMessage());
                        handler.sendEmptyMessage(HANDLER_ON);
                    }

                    @Override
                    public void onResponse(File response, int id) {
//                        OpenFileTipDialog.openFiles(downloadFile.getAbsolutePath(),YearShuilddjhActivity.this);
                        Log.e("info: ", "onResponse :" + response.getAbsolutePath());
                        L.i("success");
                        handler.sendEmptyMessage(HANDLER_OK);
                    }
                }

        );


    }

2 в AndroidMenifest.xml

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

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

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_INTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
// all user permission about download file  

3. журнал кошек покажи мне

    03-15 15:32:25.648 11709-11709/com.example.darren.fdc I/darrenli: error/storage/emulated/0/1552635145458.apk: open failed: EACCES (Permission denied) local:/storage/emulated/0/1552635145458.apk: open failed: EACCES (Permission denied) cause android.system.ErrnoException: open failed: EACCES (Permission denied) code[Ljava.lang.StackTraceElement;@2d58e5b8

4. build.gradle

  api 'com.squareup.picasso:picasso:2.5.2'
  api 'com.zhy:okhttputils:2.6.2'

    //RxVolley
    api('com.kymjs.rxvolley:rxvolley:1.1.2') {
        exclude group: 'com.squareup.okhttp3', module: 'okhttp'
        exclude group: 'com.squareup.okio'
        exclude group: 'io.reactivex'
    }
    //RxVolley下载模块
    api('com.kymjs.rxvolley:okhttp:1.1.0') {
        exclude group: 'com.squareup.okhttp3'
        exclude group: 'com.squareup.okio'
    }
    //NumberProgressBar
    api 'com.daimajia.numberprogressbar:library:1.2@aar'
    api 'io.reactivex:rxandroid:1.0.1'
    api 'io.reactivex:rxjava:1.0.14'

После этого я выполнил несколько тестов:

1-я попытка:

 private static final int REQUEST_EXTERNAL_STORAGE = 1;
    private static String[] PERMISSIONS_STORAGE = {
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.WRITE_EXTERNAL_STORAGE };

    public  void verifyStoragePermissions(Activity activity) {
                // Check if we have write permission
               int permission = ActivityCompat.checkSelfPermission(activity,
                                Manifest.permission.WRITE_EXTERNAL_STORAGE);
               L.i("error" +permission);
        L.i("error1" + PackageManager.PERMISSION_GRANTED);
               if (permission != PackageManager.PERMISSION_GRANTED) {
                        // We don't have permission so prompt the user
                       ActivityCompat.requestPermissions(activity, PERMISSIONS_STORAGE,
                                        REQUEST_EXTERNAL_STORAGE); } }

// позвоните для моего кода загрузки

2-я попытка:

 protected boolean shouldAskPermissions() {
        return (Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP_MR1);
    }

    @TargetApi(23)
    protected void askPermissions() {
        String[] permissions = {
                "android.permission.READ_EXTERNAL_STORAGE",
                "android.permission.WRITE_EXTERNAL_STORAGE"
        };
        int requestCode = 200;
        requestPermissions(permissions, requestCode);
    }

3-я попытка

public static boolean RootCommand(String command){

        Process process = null;
        DataOutputStream os = null;

        try{
            process = Runtime.getRuntime().exec("su");
            os = new DataOutputStream(process.getOutputStream());
            os.writeBytes(command + "\n");
            os.writeBytes("exit\n");
            os.flush();
            process.waitFor();
        } catch (Exception e){
            return false;
        } finally{
            if (os != null){
                try {
                    os.close();
                }catch (IOException e){
                    e.printStackTrace();
                }
            }
            if(process!=null) {
                process.destroy();
            }
        }
        return true;
    }


   String apkRoot="chmod 777 "+path;

UpdateActivity.RootCommand (apkRoot);