中间件为过滤进入应用程序的HTTP请求提供了一种方便的机制。例如，Laravel 内置了一个中间件来验证用户的身份认证。如果用户没有通过身份认证，中间件会将用户重定向到登录界面。但是，如果用户被认证，中间件将允许该请求进一步进入该应用。

当然，除了身份认证以外，还可以编写另外的中间件来执行各种任务。例如：CORS 中间件可以负责为所有离开应用的响应添加合适的头部信息；日志中间件可以记录所有传入应用的请求。

Laravel 自带了一些中间件，包括身份验证、CSRF 保护等。所有这些中间件都位于 app/Http/Middleware 目录。

web.php

<?php
/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/
Route::group([
    'middleware' => ['api', 'CheckParam'],
    'prefix' => 'h5',
    //'namespace' => '\App\Http\Controllers'
], function () {
Route::get('/', function () {
    return view('welcome');
});
Route::get('/blog', '\Modules\Blog\Http\Controllers\BlogController@index');
Auth::routes();
Route::get('/home', 'HomeController@index')->name('home');
Route::redirect('/testtest', '/', 301);
//Route::get('user/{id}', function ($id) {
//    return 'User '.$id;
//});
//Route::get('show/{id}/{classid}', 'HomeController@index');
//Route::get('user/{name}', function ($name) {
//    //
//})->where('name', '[A-Za-z]+');
Route::get('user/{username}', 'HomeController@index')->where('username', '[a-z]+');
Route::get('show/{id}', 'HomeController@show');
//Route::get('show/{id}', 'HomeController@show')->where('id', '[0-9]+');
//Route::get('user/{id}/{name}', function ($id, $name) {
//    //
//})->where(['id' => '[0-9]+', 'name' => '[a-z]+']);
});
?>
app/http/kernel.php
<?php
protected $routeMiddleware = [       
        'CheckParam' => \App\Http\Middleware\CheckParam::class,
    ];
?>
HomeController.php
<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
class HomeController extends Controller
{
    /**
     * Create a new controller instance.
     * @return void
     */
    public function __construct()
    {
        //$this->middleware('auth');
    }
    /**
     * Show the application dashboard.
     * @return \Illuminate\Http\Response
     */
    public function index($username)
    {
        echo "username=>".$username;
        //return view('home');
    }
    public function show($id){
        echo "show_id=>".$id;
    }
}
?>
app/http/middleware/CheckParam.php
<?php
namespace App\Http\Middleware;
use Closure;
use Illuminate\Http\Request;
use ZM\ApiResponse\Facades\ApiResponse;
class CheckParam
{
    /**
     * Handle an incoming request.
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle(Request $request, Closure $next)
    {
        if(isset($request->id) && !preg_match("/^[1-9][0-9]*$/",$request->id)){
            echo "exit";exit;            
            //return ApiResponse::failure(10010, config('errcode.10010'));
        }
        if(isset($request->master_id) && !preg_match("/^[1-9][0-9]*$/",$request->master_id)){
            //return ApiResponse::failure(10010, config('errcode.10010'));
        }
        if(isset($request->type) && !preg_match("/^[1,2]*$/",$request->type)){
            //return ApiResponse::failure(10010, config('errcode.10010'));
        }
        return $next($request);
    }
}
?>

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