android - Oreo (WRITE EXTERNAL STORAGE) Permission

Question

According to "developer.android.com"

If the app targets Android 8.0 (API level 26), the system grants only 
READ_EXTERNAL_STORAGE at that time; however, if the app later requests 
WRITE_EXTERNAL_STORAGE, the system immediately grants that privilege 
without prompting the user.

Now, I have the READ_EXTERNAL_STORAGE and I'm requesting the DownloadManager to download a file in the Public Download folder

downloadRequest.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, mAttachmentItem.getFilename());

Unfortunately, I got

E/UncaughtException: java.lang.IllegalStateException: Unable to create directory: /storage/emulated/0/data/user/0/com.abc.cba/files
                                                                           at android.app.DownloadManager$Request.setDestinationInExternalPublicDir(DownloadManager.java:699)

I have declared both of permissions in the Manifest

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

Read permission is already Granted and in Runtime I'm requesting Write permission, the system doesn't prompt any message or dialog, it's always Denied(Not Granted) in "onRequestPermissionsResult"

public static boolean isPermissionsToAccessStorageAreGranted(Context context, Activity activity) {
    ArrayList<String> permissions = new ArrayList<>();

    if (!PermissionUtil.checkPermissions(context, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
        permissions.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
    }

    if (!permissions.isEmpty()) {
        String[] permissionsList = permissions.toArray(new String[permissions.size()]);
        PermissionUtil.requestPermissions(activity, permissionsList,
                PermissionUtil.REQUESTCODE_ACCESS_STORAGE);
        return false;
    } else {
        return true;
    }
}


@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if(requestCode==REQUESTCODE_ACCESS_STORAGE && grantResults[0]== PackageManager.PERMISSION_GRANTED){
 /* downloadFile(); */       
    }
}

I'm trying to grant those two permissions via ADB, it shows me an error:

adb shell pm grant com.abc.cba 
android.permission.WRITE_EXTERNAL_STORAGE
Operation not allowed: java.lang.SecurityException: Package com.abc.cbs 
has not requested permission android.permission.WRITE_EXTERNAL_STORAGE

adb shell pm grant com.abc.cba 
android.permission.READ_EXTERNAL_STORAGE
Operation not allowed: java.lang.SecurityException: Can't change 
android.permission.READ_EXTERNAL_STORAGE. It is required by the 
application

Answer 1

Actually, It was an external problem. One of App Libs I'm using request the WRITE_EXTERNAL_PERMISSION with android:maxSdkVersion. So when merging with my Manifest it will remove the permission for the whole application.

The Solution is to add:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" tools:node="replace"/>