Laravel 5.5 change unauthenticated login redirect url

But in Laravel 5.5 this has been moved to this location vendor/laravel/framework/src/Illuminate/Foundation/Exceptions/Handler.php so how can I change it now? I don't want to change stuff in the vendor directory encase it gets overridden by composer updates.

We need to just include the use Illuminate\Auth\AuthenticationException;

and then it works as in laravel 5.4

Here's how I solved it. In render function I caught exception class. And in case if it's Authentication exception class I wrote my code for redirect (the code I would write in unauthenticated function in previous version).

public function render($request, Exception $exception)
{
    $class = get_class($exception);

    switch($class) {
        case 'Illuminate\Auth\AuthenticationException':
            $guard = array_get($exception->guards(), 0);
            switch ($guard) {
                case 'admin':
                    $login = 'admin.login';
                    break;
                default:
                    $login = 'login';
                    break;
            }

            return redirect()->route($login);
    }

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

But in Laravel 5.5 this has been moved to this location vendor/laravel/framework/src/Illuminate/Foundation/Exceptions/Handler.php so how can I change it now? I don't want to change stuff in the vendor directory encase it gets overridden by composer updates.

It's just the case that the function is not there by default anymore.

You can just override it as you did in 5.4. Just make sure to include

use Exception;
use Request;
use Illuminate\Auth\AuthenticationException;
use Response;

in the Handler file.

For Example my app/Exceptions/Handler.php looks somewhat like this:

<?php
    namespace App\Exceptions;
    use Exception;
    use Request;
    use Illuminate\Auth\AuthenticationException;
    use Response;
    use Illuminate\Foundation\Exceptions\Handler as ExceptionHandler;
    class Handler extends ExceptionHandler
    {
        (...) // The dfault file content
        /**
         * Convert an authentication exception into a response.
         *
         * @param  \Illuminate\Http\Request  $request
         * @param  \Illuminate\Auth\AuthenticationException  $exception
         * @return \Illuminate\Http\Response
         */
         protected function unauthenticated($request, AuthenticationException $exception)
         {
            return $request->expectsJson()
                    ? response()->json(['message' => 'Unauthenticated.'], 401)
                    : redirect()->guest(route('authentication.index'));
    }
}