Laravel Api表单验证失败被重定向到主页

    /**
     * Handle a failed validation attempt.
     *
     * @param  \Illuminate\Contracts\Validation\Validator  $validator
     * @return void
     *
     * @throws \Illuminate\Validation\ValidationException
     */
    protected function failedValidation(Validator $validator)
    {
        throw (new ValidationException($validator))
                    ->errorBag($this->errorBag)
                    ->redirectTo($this->getRedirectUrl());
    }

    /**
     * Get the URL to redirect to on a validation error.
     *
     * @return string
     */
    protected function getRedirectUrl()
    {
        $url = $this->redirector->getUrlGenerator();

        if ($this->redirect) {
            return $url->to($this->redirect);
        } elseif ($this->redirectRoute) {
            return $url->route($this->redirectRoute);
        } elseif ($this->redirectAction) {
            return $url->action($this->redirectAction);
        }

        return $url->previous();
    }

php artisan make:request ApiRequest

    protected function failedValidation(Validator $validator)
    {
        throw new HttpResponseException(response()->json([
            'error' => (new ValidationException($validator))->errors()
        ], JsonResponse::HTTP_UNPROCESSABLE_ENTITY));
    }

class RegisterRequest extends ApiRequest
{
    // 省略
}