How permission can be checked at runtime without t

Question

I design a function that may get/set a resource from SD and if not found from sd then take it from Asset and if possible write the asset back to SD
This function may check by method invocation if SD is mounted and accessible...

boolean bSDisAvalaible = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);

My designed function may be used from one app(project) to another (with or without android.permission.WRITE_EXTERNAL_STORAGE)

Then I would like to check if the current application has this particular permission without playing with SecurityException.

Does it exist a "nice" way to consult current defined permissions at runtime ?

Answer 1

Sharing my methods in case someone needs them:

 /** Determines if the context calling has the required permission
 * @param context - the IPC context
 * @param permissions - The permissions to check
 * @return true if the IPC has the granted permission
 */
public static boolean hasPermission(Context context, String permission) {

    int res = context.checkCallingOrSelfPermission(permission);

    Log.v(TAG, "permission: " + permission + " = \t\t" + 
    (res == PackageManager.PERMISSION_GRANTED ? "GRANTED" : "DENIED"));

    return res == PackageManager.PERMISSION_GRANTED;

}

/** Determines if the context calling has the required permissions
 * @param context - the IPC context
 * @param permissions - The permissions to check
 * @return true if the IPC has the granted permission
 */
public static boolean hasPermissions(Context context, String... permissions) {

    boolean hasAllPermissions = true;

    for(String permission : permissions) {
        //you can return false instead of assigning, but by assigning you can log all permission values
        if (! hasPermission(context, permission)) {hasAllPermissions = false; }
    }

    return hasAllPermissions;

}

And to call it:

boolean hasAndroidPermissions = SystemUtils.hasPermissions(mContext, new String[] {
                android.Manifest.permission.ACCESS_WIFI_STATE,
                android.Manifest.permission.READ_PHONE_STATE,
                android.Manifest.permission.ACCESS_NETWORK_STATE,
                android.Manifest.permission.INTERNET,
        });

Answer 2

You can also use this:

private boolean doesUserHavePermission()
{
    int result = context.checkCallingOrSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE);
    return result == PackageManager.PERMISSION_GRANTED;
}

Answer 3

The code which works fine for me is :-

  final int MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE = 102;
  if ((ContextCompat.checkSelfPermission(getActivity(),Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)) {

                requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                        MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
            } else {
        // user already provided permission
                // perform function for what you want to achieve
     }

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {

    boolean canUseExternalStorage = false;

    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE: {
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                canUseExternalStorage = true;
            }

            if (!canUseExternalStorage) {
                Toast.makeText(getActivity(), "Cannot use this feature without requested permission", Toast.LENGTH_SHORT).show();
            } else {
                // user now provided permission
                // perform function for what you want to achieve
            }
        }
      }
 }

Answer 4

You should check for permissions in the following way (as described here Android permissions):

int result = ContextCompat.checkSelfPermission(getContext(), Manifest.permission.READ_PHONE_STATE);

then, compare your result to either:

result == PackageManager.PERMISSION_DENIED

or:

result == PackageManager.PERMISSION_GRANTED

Answer 5

This is another solution as well

PackageManager pm = context.getPackageManager();
int hasPerm = pm.checkPermission(
    android.Manifest.permission.WRITE_EXTERNAL_STORAGE, 
    context.getPackageName());
if (hasPerm != PackageManager.PERMISSION_GRANTED) {
   // do stuff
}

Answer 6

You can use Context.checkCallingorSelfPermission() function for this. Here is an example:

private boolean checkWriteExternalPermission()
{
    String permission = android.Manifest.permission.WRITE_EXTERNAL_STORAGE;
    int res = getContext().checkCallingOrSelfPermission(permission);
    return (res == PackageManager.PERMISSION_GRANTED);            
}