public function handle($request, Closure $next)
    {
        try {
            if ($this->validator->validateRequest($request)) {
                $this->app->singleton(LaravelExceptionHandler::class, function ($app) {
                    return $app[ExceptionHandler::class];
                });

                $request = $this->app->make(RequestContract::class)->createFromIlluminate($request);

                $this->events->fire(new RequestWasMatched($request, $this->app));

                return $this->sendRequestThroughRouter($request);
            }
        } catch (Exception $exception) {
            $this->exception->report($exception);

            return $this->exception->handle($exception);
        }

        return $next($request);
    }Copy

    protected function sendRequestThroughRouter(HttpRequest $request)
    {
        $this->app->instance('request', $request);

        return (new Pipeline($this->app))->send($request)->through($this->middleware)->then(function ($request) {
            return $this->router->dispatch($request);
        });
    }Copy

public function boot()
    {
        ...

        $kernel = $this->app->make(Kernel::class);

        $this->app[Request::class]->mergeMiddlewares(
            $this->gatherAppMiddleware($kernel)
        );Copy

return $this->router->dispatch($request);Copy

    public function dispatch(Request $request)
    {
        ...

        try {
            $response = $this->adapter->dispatch($request, $request->version());
        } catch (Exception $exception) {
            ...
        }

        return $this->prepareResponse($response, $request, $request->format());
    }Copy

    public function dispatch(Request $request, $version)
    {
        if (! isset($this->routes[$version])) {
            throw new UnknownVersionException;
        }

        $routes = $this->mergeOldRoutes($version);

        $this->router->setRoutes($routes);

        $router = clone $this->router;

        $response = $router->dispatch($request);

        unset($router);

        return $response;
    }Copy

...
$middleware = $shouldSkipMiddleware ? [] : $this->gatherRouteMiddleware($route);
...Copy

    public function gatherRouteMiddleware(Route $route)
    {
        $middleware = collect($route->gatherMiddleware())->map(function ($name) {
            return (array) MiddlewareNameResolver::resolve($name, $this->middleware, $this->middlewareGroups);
        })->flatten();

        return $this->sortMiddleware($middleware);
    }Copy

    public function gatherMiddleware()
    {
        ...

        return $this->computedMiddleware = array_unique(array_merge(
            $this->middleware(), $this->controllerMiddleware()
        ), SORT_REGULAR);
    }Copy

    public function middleware($middleware = null)
    {
        if (is_null($middleware)) {
            return (array) ($this->action['middleware'] ?? []);
        }

        ...
        return $this;
    }Copy

...
$route = $this->newRoute(
    $methods, $this->prefix($uri), $action
);
//由于此url属于web中间件组
if ($this->hasGroupStack()) {
    $this->mergeGroupAttributesIntoRoute($route);
}Copy

  array (
    0 => 'App\\Http\\Middleware\\EncryptCookies',
    1 => 'Illuminate\\Routing\\Middleware\\SubstituteBindings',
    2 => 'Illuminate\\Cookie\\Middleware\\AddQueuedCookiesToResponse',
    3 => 'Illuminate\\Session\\Middleware\\StartSession',
    4 => 'Illuminate\\View\\Middleware\\ShareErrorsFromSession',
    5 => 'App\\Http\\Middleware\\VerifyCsrfToken',
    6 => 'App\\Http\\Middleware\\RecordLastActivedTime',
    7 => 'App\\Http\\Middleware\\RedirectIfAuthenticated',
  )Copy

    public function addRoute($methods, $uri, $action)
    {
        ...
        //获得routes/api.php中定义的嵌套group路由的中间件
        $action = $this->mergeLastGroupAttributes($action);
        //添加一个preparation controller中间件
        $action = $this->addControllerMiddlewareToRouteAction($action);
        ...
        return $this->adapter->addRoute((array) $methods, $action['version'], $uri, $action);
    }

    public function addRoute(array $methods, array $versions, $uri, $action)
    {
        $this->createRouteCollections($versions);

        $route = new Route($methods, $uri, $action);
        $route->where($action['where']);

        foreach ($versions as $version) {
            $this->routes[$version]->add($route);
        }

        return $route;
    }Copy

    ‌array (
        0 => 'Dingo\\Api\\Http\\Middleware\\PrepareController',
        1 => 'Liyu\\Dingo\\SerializerSwitch:array',
        2 => 'Illuminate\\Routing\\Middleware\\SubstituteBindings',
        3 => 'Dingo\\Api\\Http\\Middleware\\RateLimit',
        4 => 'Dingo\\Api\\Http\\Middleware\\Auth',
    )Copy

    public function dispatch(Request $request)
    {
        ...
        try {
            $response = $this->adapter->dispatch($request, $request->version());
        } catch (Exception $exception) {
            ...
        }

        return $this->prepareResponse($response, $request, $request->format());
    }Copy

    protected function prepareResponse($response, Request $request, $format)
    {
        if ($response instanceof IlluminateResponse) {
            $response = Response::makeFromExisting($response);
        } elseif ($response instanceof JsonResponse) {
            $response = Response::makeFromJson($response);
        }

        if ($response instanceof Response) {
            // If we try and get a formatter that does not exist we'll let the exception
            // handler deal with it. At worst we'll get a generic JSON response that
            // a consumer can hopefully deal with. Ideally they won't be using
            // an unsupported format.
            try {
                $response->getFormatter($format)->setResponse($response)->setRequest($request);
            } catch (NotAcceptableHttpException $exception) {
                return $this->exception->handle($exception);
            }

            $response = $response->morph($format);
        }

        if ($response->isSuccessful() && $this->requestIsConditional()) {
            if (! $response->headers->has('ETag')) {
                $response->setEtag(sha1($response->getContent()));
            }

            $response->isNotModified($request);
        }

        return $response;
    }Copy