// Assume thisActivity is the current activity

int permissionCheck = ContextCompat.checkSelfPermission(thisActivity,

        Manifest.permission.WRITE_CALENDAR);

// Here, thisActivity is the current activity

if (ContextCompat.checkSelfPermission(thisActivity,

                Manifest.permission.READ_CONTACTS)

        != PackageManager.PERMISSION_GRANTED) {

    // Should we show an explanation?

    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,

            Manifest.permission.READ_CONTACTS)) {

        // Show an expanation to the user *asynchronously* -- don't block

        // this thread waiting for the user's response! After the user

        // sees the explanation, try again to request the permission.

    } else {

        // No explanation needed, we can request the permission.

        ActivityCompat.requestPermissions(thisActivity,

                new String[]{Manifest.permission.READ_CONTACTS},

                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an

        // app-defined int constant. The callback method gets the

        // result of the request.

    }

}

@Override

public void onRequestPermissionsResult(int requestCode,

        String permissions[], int[] grantResults) {

    switch (requestCode) {

        case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {

            // If request is cancelled, the result arrays are empty.

            if (grantResults.length > 0

                && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! Do the

                // contacts-related task you need to do.

            } else {

                // permission denied, boo! Disable the

                // functionality that depends on this permission.

            }

            return;

        }

        // other 'case' lines to check for other

        // permissions this app might request

    }

}

Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_WRITE_SETTINGS);

intent.setData(Uri.parse("package:" + getPackageName()));

intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

startActivity(intent);