How does Laravel5.x get 404 to return a json?

For example, for a normal request, the return method is as follows: {code...} abnormal request. For example, the route is not defined and the request method is not defined. How can I return a json object? It is definitely not appropriate to write it in 404. blade. php, because if it is written in, a string is returned, for example, a normal request. The return method is as follows:

Return response ($ result, $ code); // return json

Abnormal request. For example, the route is not defined and the request method is not defined. How can I return a json object? It is definitely not suitable to write it in 404. blade. php, because if it is written in, a string will be returned.

Reply content:

For example, for a normal request, the return method is as follows:

Return response ($ result, $ code); // return json

Abnormal request. For example, the route is not defined and the request method is not defined. How can I return a json object? It is definitely not suitable to write it in 404. blade. php, because if it is written in, a string will be returned.

InMiddlewareOrApp\Exceptions\HandlerCapture
Symfony\Component\HttpKernel\Exception\NotFoundHttpException

For Middleware

use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;public function handle($request, Closure $next) {    try {        return $next($request);    } catch (NotFoundHttpException $e) {        return response()->json(['msg'=>'NotFound']);    }}