关于laravel的Authenticate中间件理解

先来看一下，源代码改忘了，差不多看看

class Authenticate extends Middleware
{
    protected function redirectTo($request)
    {

        return route("/login");
    }
}

查看继承的父类得知

<?php

namespace Illuminate\Auth\Middleware;

use Closure;
use Illuminate\Auth\AuthenticationException;
use Illuminate\Contracts\Auth\Factory as Auth;
use Illuminate\Contracts\Auth\Middleware\AuthenticatesRequests;

class Authenticate implements AuthenticatesRequests
{
    /**
     * The authentication factory instance.
     *
     * @var \Illuminate\Contracts\Auth\Factory
     */
    protected $auth;

    /**
     * Create a new middleware instance.
     *
     * @param  \Illuminate\Contracts\Auth\Factory  $auth
     * @return void
     */
    public function __construct(Auth $auth)
    {
        $this->auth = $auth;
    }

    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @param  string[]  ...$guards
     * @return mixed
     *
     * @throws \Illuminate\Auth\AuthenticationException
     */
    public function handle($request, Closure $next, ...$guards)
    {
        $this->authenticate($request, $guards);

        return $next($request);
    }

    /**
     * Determine if the user is logged in to any of the given guards.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  array  $guards
     * @return void
     *
     * @throws \Illuminate\Auth\AuthenticationException
     */
    protected function authenticate($request, array $guards)
    {
        if (empty($guards)) {
            $guards = [null];
        }

        foreach ($guards as $guard) {
            if ($this->auth->guard($guard)->check()) {
                return $this->auth->shouldUse($guard);
            }
        }

        $this->unauthenticated($request, $guards);
    }

    /**
     * Handle an unauthenticated user.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  array  $guards
     * @return void
     *
     * @throws \Illuminate\Auth\AuthenticationException
     */
    protected function unauthenticated($request, array $guards)
    {
        throw new AuthenticationException(
            'Unauthenticated.', $guards, $this->redirectTo($request)
        );
    }

    /**
     * Get the path the user should be redirected to when they are not authenticated.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return string|null
     */
    protected function redirectTo($request)
    {
        //
    }
}

1. redirectTo会被返回

2. 抛出异常会被foundation中的exception的handle的render方法捕获，会再次调用判断accept中是否含有/json +json这两个，如果没有就返回redirectTo的route

   // 系统的捕获函数，通过$exception获取directTo返回达到即使Authenticate即使为空也会跳转的效果
   protected function unauthenticated($request, AuthenticationException $exception)
   {
       return $this->shouldReturnJson($request, $exception)
           ? response()->json(['message' => $exception->getMessage()], 401)
           : redirect()->guest($exception->redirectTo() ?? route('login'));
   }

3. 中间件处理方法中，有判断返回是否为response的功能，因此如果要在中间件中返回响应只有在handle中return repsonse，类中其他方法调用return response无效
4. 应该可以通过在redirectTo中抛出其他异常达到自定义响应功能，当然异常不能为UnauthorizedException，否则依旧会被捕获
5. app/Exceptions 是用来定义错误类型的，对于错误的捕获和响应只能在handler的render函数中操作