public abstract class BaseActivity extends AppCompatActivity {
    private Map<Integer, PermissionCallback> permissionCallbackMap = new HashMap<>();

    @Override
    protected void onStart() {
        super.onStart();
        ...
    }

    @Override
    public void setContentView(int layoutResId) {
        super.setContentView(layoutResId);
        bindViews();
    }

    ...

    @Override
    public void onRequestPermissionsResult(
            int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        PermissionCallback callback = permissionCallbackMap.get(requestCode);

        if (callback == null) return;

        // Check whether the permission request was rejected.
        if (grantResults.length < 0 && permissions.length > 0) {
            callback.onPermissionDenied(permissions);
            return;
        }

        List<String> grantedPermissions = new ArrayList<>();
        List<String> blockedPermissions = new ArrayList<>();
        List<String> deniedPermissions = new ArrayList<>();
        int index = 0;

        for (String permission : permissions) {
            List<String> permissionList = grantResults[index] == PackageManager.PERMISSION_GRANTED
                    ? grantedPermissions
                    : ! ActivityCompat.shouldShowRequestPermissionRationale(this, permission)
                        ? blockedPermissions
                        : deniedPermissions;
            permissionList.add(permission);
            index ++;
        }

        if (grantedPermissions.size() > 0) {
            callback.onPermissionGranted(
                    grantedPermissions.toArray(new String[grantedPermissions.size()]));
        }

        if (deniedPermissions.size() > 0) {
            callback.onPermissionDenied(
                    deniedPermissions.toArray(new String[deniedPermissions.size()]));
        }

        if (blockedPermissions.size() > 0) {
            callback.onPermissionBlocked(
                    blockedPermissions.toArray(new String[blockedPermissions.size()]));
        }

        permissionCallbackMap.remove(requestCode);
    }

    /**
     * Check whether a permission is granted or not.
     *
     * @param permission
     * @return
     */
    public boolean hasPermission(String permission) {
        return ContextCompat.checkSelfPermission(this, permission) == PackageManager.PERMISSION_GRANTED;
    }

    /**
     * Request permissions and get the result on callback.
     *
     * @param permissions
     * @param callback
     */
    public void requestPermission(String [] permissions, @NonNull PermissionCallback callback) {
        int requestCode = permissionCallbackMap.size() + 1;
        permissionCallbackMap.put(requestCode, callback);
        ActivityCompat.requestPermissions(this, permissions, requestCode);
    }

    /**
     * Request permission and get the result on callback.
     *
     * @param permission
     * @param callback
     */
    public void requestPermission(String permission, @NonNull PermissionCallback callback) {
        int requestCode = permissionCallbackMap.size() + 1;
        permissionCallbackMap.put(requestCode, callback);
        ActivityCompat.requestPermissions(this, new String[] { permission }, requestCode);
    }
}

private void requestLocationAfterPermissionCheck() {
    if (hasPermission(Manifest.permission.ACCESS_FINE_LOCATION)) {
        requestLocation();
        return;
    }

    // Call the base class method.
    requestPermission(Manifest.permission.ACCESS_FINE_LOCATION, new PermissionCallback() {
        @Override
        public void onPermissionGranted(String[] grantedPermissions) {
            requestLocation();
        }

        @Override
        public void onPermissionDenied(String[] deniedPermissions) {
            // Do something.
        }

        @Override
        public void onPermissionBlocked(String[] blockedPermissions) {
            // Do something.
        }
    });
}