本文实例讲述了Laravel5.1框架注册中间件的三种场景。分享给大家供大家参考，具体如下：
在Laravel中注册中间件主要有三种场景，一种给控制器中的方法进行注册，一种是给整个控制器进行注册，最后一种是给全局注册中间件。
- 1、在控制器中的方法中注册中间件
这种需求是最为常见，这个例子是给IndexController中的index方法添加中间件。
Route::get('/', ['middleware'=>['App\Http\Middleware\EmailMiddleware'],'uses'=>'IndexController@index']);
- 2、在整个控制器中注册中间件
这种需求有的时候也会出现，如果给整个控制器中注册中间件，那么这个控制器中的所有方法都注册了该中间件。跟我一起来找到答案！
控制器基类（Controller.php）
首先来看一下控制器基类，可以看到Controller类继承了BaseController类，而BaseController的路径是Illuminate\Routing\Controller，然后我们来看看Laravel的源码。
<?php
namespace App\Http\Controllers;
use Illuminate\Foundation\Bus\DispatchesJobs;
use Illuminate\Routing\Controller as BaseController;
use Illuminate\Foundation\Validation\ValidatesRequests;
use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
abstract class Controller extends BaseController
{
use AuthorizesRequests, DispatchesJobs, ValidatesRequests;
}
BaseController类
从源码中我们可以看到有一个属性为middleware，这个middleware属性就是我们要找的，所以只要在需要注册的控制器下使用这个属性即可完成注册。
protected $middleware = [];
<?php
namespace Illuminate\Routing;
use BadMethodCallException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
abstract class Controller
{
/**
* The middleware registered on the controller.
*
* @var array
*/
protected $middleware = [];
/**
* Register middleware on the controller.
*
* @param array|string|\Closure $middleware
* @param array $options
* @return \Illuminate\Routing\ControllerMiddlewareOptions
*/
public function middleware($middleware, array $options = [])
{
foreach ((array) $middleware as $m) {
$this->middleware[] = [
'middleware' => $m,
'options' => &$options,
];
}
return new ControllerMiddlewareOptions($options);
}
/**
* Get the middleware assigned to the controller.
*
* @return array
*/
public function getMiddleware()
{
return $this->middleware;
}
/**
* Execute an action on the controller.
*
* @param string $method
* @param array $parameters
* @return \Symfony\Component\HttpFoundation\Response
*/
public function callAction($method, $parameters)
{
return call_user_func_array([$this, $method], $parameters);
}
/**
* Handle calls to missing methods on the controller.
*
* @param array $parameters
* @return mixed
*
* @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
*/
public function missingMethod($parameters = [])
{
throw new NotFoundHttpException('Controller method not found.');
}
/**
* Handle calls to missing methods on the controller.
*
* @param string $method
* @param array $parameters
* @return mixed
*
* @throws \BadMethodCallException
*/
public function __call($method, $parameters)
{
throw new BadMethodCallException("Method [{$method}] does not exist.");
}
给整个控制器注册中间件
我们选用系统的Authenticate中间件来举例，这个中间件是用于检测用户是否登录。
注意：中间件的名称为键，值可以是一个空数组
protected $middleware = ['\App\Http\Middleware\Authenticate'=>[]];
- 3、全局注册中间件
打开app/Http/Kernel.php，这是一个内核文件，可以看到一个属性$middleware，我们只需要将我们自定义的中间件的路径添加到这个$middleware 这个属性中即可。
此外还有一个$routeMiddleware属性，使用这个属性可以根据路由来注册中间件。 我们的路由有：goods/info，goods/detail两个路由器 我们可以将$routeMiddleware属性添加一行
'goods.*' => \App\Http\Middleware\GoodsMiddleware::class,
<?php
namespace App\Http;
use Illuminate\Foundation\Http\Kernel as HttpKernel;
class Kernel extends HttpKernel
{
/**
* The application's global HTTP middleware stack.
*
* @var array
*/
protected $middleware = [
\Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,
\App\Http\Middleware\EncryptCookies::class,
\Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
\Illuminate\Session\Middleware\StartSession::class,
\Illuminate\View\Middleware\ShareErrorsFromSession::class,
\App\Http\Middleware\VerifyCsrfToken::class,
];
/**
* The application's route middleware.
*
* @var array
*/
protected $routeMiddleware = [
'auth' => \App\Http\Middleware\Authenticate::class,
'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
];
}