Php Laravel未捕获异常

我试图从包中的中间件捕获异常：

public function authenticate(Request $request)
{
    $this->checkForToken($request);

    try {
        if (! $this->auth->parseToken()->authenticate()) {
            throw new UnauthorizedHttpException('jwt-auth', 'User not found');
        }
    } catch (JWTException $e) {
        throw new UnauthorizedHttpException('jwt-auth', $e->getMessage(), $e, $e->getCode());
    }
}

我尝试捕获异常处理程序：

public function render($request, Exception $exception)
{
    //dd($exception);
    if ($exception instanceof UnauthorizedHttpException) {

        return response()->json($exception->getMessage(), $exception->getStatusCode());

    } 

    return parent::render($request, $exception);
}    

但一点也没有。例外情况的dd如下：

UnauthorizedHttpException {#231 ▼
-statusCode: 401
-headers: array:1 [▶]
#message: "Token has expired"
#code: 0
#file: "/home/vagrant/codementor/vendor/tymon/jwt- auth/src/Http/Middleware/BaseMiddleware.php"
#line: 74
-previous: TokenExpiredException {#237 ▶}
trace: {▶}
}

---

哪个laravel版本5？它没有响应json？