极客笔记Laravel 中间件
中间件作为用户和请求之间的一层。这意味着当用户请求服务器时，请求会经过中间件，然后中间件验证请求是否已经认证。如果用户请求已经认证，请求会被发送到后端。如果用户请求未经认证，那么中间件会将用户重定向到登录界面。
另外一个中间件可以用于执行各种任务，除了认证之外。例如，CORS中间件负责在所有的响应中添加头部。
Laravel 框架包含多个中间件，例如身份验证和CSRF保护，它们都位于 app/Http/Middleware 目录下。
我们可以说中间件是一个 HTTP 请求过滤器，您可以在其中进行条件检查。
在中间件中，我们将讨论以下主题：
- 创建一个中间件
- 应用中间件
- 在中间件中检查条件
- 路由中间件
创建一个中间件
输入以下命令 php artisan make:middleware ‘中间件名称’ 。
要查看是否已创建 CheckAge 中间件，请转到您的项目。我们的项目名称是 laravelproject，因此中间件的路径将为： C:\xampp\htdocs\laravelproject\app\Http\Middleware 。
应用中间件
中间件可以应用于所有URL或某些特定URL。
让我们把中间件应用于所有URL。
步骤1： 打开kernel.php文件。如果我们想要应用中间件于所有URL，那么将中间件的路径添加到中间件数组中。
<?php
namespace App\Http;
use Illuminate\Foundation\Http\Kernel as HttpKernel;
class Kernel extends HttpKernel
{
/**
* The application's global HTTP middleware stack.
*
* These middleware are run during every request to your application.
*
* @var array
*/
protected middleware = [ \Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,
\Illuminate\Foundation\Http \Middleware\ValidatePostSize::class,
\App\Http\Middleware\TrimStrings::class,
\App\Http\Middleware\CheckAge
::class,
\Illuminate\Foundation\Http\Middleware\ConvertEmptyStringsToNull::class,
];
/**
* The application's route middleware groups.
*
* @var array
*/
protectedmiddlewareGroups = [
'web' => [
\App\Http\Middleware\EncryptCookies::class,
\Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
\Illuminate\Session\Middleware\StartSession::class,
// \Illuminate\Session\Middleware\AuthenticateSession::class,
\Illuminate\View\Middleware
\ShareErrorsFromSession::class,
\App\Http\Middleware\VerifyCsrfToken::class,
\Illuminate\Routing\Middleware\SubstituteBindings::class,
],
'api' => [
'throttle:60,1',
'bindings',
],
];
/**
* The application's route middleware.
*
* These middleware may be assigned to groups or used individually.
*
*
@var array
*/
protected $routeMiddleware = [
'auth' => \Illuminate\Auth\Middleware\Authenticate::class,
'auth.basic' => \Illuminate\Auth\Middleware
\AuthenticateWithBasicAuth::class,
'bindings' => \Illuminate\Routing\Middleware\SubstituteBindings::class,
'can' => \Illuminate\Auth\Middleware\Authorize::class,
'guest' => \App\Http\Middleware
\RedirectIfAuthenticated::class,
'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
];
}
步骤2： 在 Git Bash 窗口中输入命令 php artisan serve 。
步骤3： 打开您已经创建为中间件的 CheckAge.php 文件。
<?php
namespace App\Http\Middleware;
use Closure;
class CheckAge
{
/**
* Handle an incoming request.
*
* @param \Illuminate\Http
\Request request
* @param \Closurenext
* @return mixed
*/
public function handle(request, Closurenext)
{
//return "middleware";
echo "hello world";
return next(request);
}
}
步骤4： 现在，输入网址 ‘ http://localhost/laravelproject/public/ ‘。
让我们将中间件应用于一些特定的路由。
步骤1： 打开kernel.php文件。如果我们想要将中间件应用于一些特定的路由
<?php
namespace App\Http;
use Illuminate\Foundation\Http\Kernel as HttpKernel;
class Kernel extends HttpKernel
{
/**
* The application's global HTTP middleware stack.
*
* These middleware are run during every request to your application.
*
* @var array
*/
protected middleware = [
\Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,
\Illuminate\Foundation\Http\Middleware\ValidatePostSize::class,
\App\Http\Middleware\TrimStrings::class,
\Illuminate\Foundation\Http\Middleware\ConvertEmptyStringsToNull::class,
];
/**
* The application's route middleware groups.
*
* @var array
*/
protectedmiddlewareGroups = [
'web' => [
\App\Http\Middleware\EncryptCookies::class,
\Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
\Illuminate\Session\Middleware\StartSession::class,
// \Illuminate\Session\Middleware\AuthenticateSession::class,
\Illuminate\View\Middleware \ShareErrorsFromSession::class,
\App\Http\Middleware\VerifyCsrfToken::class,
\Illuminate\Routing\Middleware\SubstituteBindings::class,
],
'api' => [
'throttle:60,1',
'bindings',
],
];
/**
* The application's route middleware.
*
* These middleware may be assigned to groups or used individually.
*
*
@var array
*/
protected $routeMiddleware = [
'auth' => \Illuminate\Auth\Middleware\Authenticate::class,
'auth.basic' => \Illuminate\Auth\Middleware
\AuthenticateWithBasicAuth::class,
'bindings' => \Illuminate\Routing\Middleware\SubstituteBindings::class,
'can' => \Illuminate\Auth\Middleware\Authorize::class,
'guest' => \App\Http\Middleware
\RedirectIfAuthenticated::class,
'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
'age' => \App\Http\Middleware\CheckAge::class ];
}
在上面的代码中，我们添加了代码，即： ‘age’ => \App\Http\Middleware\CheckAge::class’ ，其中age是中间件的名称。现在，我们可以在一些特定的路由中使用’age’中间件。
步骤2： 打开你创建的中间件文件 CheckAge.php 。
步骤3： 在 web.php 文件中添加中间件代码。
Route::Get('/',function()
{
return view('welcome');
})-> middleware('age');
Route::Get('user/profile',function()
{
return "user profile";
});
在以上代码中，我们在’/’根URL中添加了中间件，而在’user/profile’ URL中没有添加中间件。
输出：
当我们访问根URL时，输出将为：
上述输出显示中间件代码也已被访问，因为它显示了一个”hello world”。
当我们访问URL，即/user/profile时，输出将是：
以上输出表明中间件代码未被访问。
当参数通过URL传递时。
web.php
Route::Get('/{age}',function($age)
{
return view('welcome');
})-> middleware('age');
检查年龄.php
<?php
namespace App\Http\Middleware;
use Closure;
class CheckAge
{
/**
* Handle an incoming request.
*
* @param
\Illuminate\Http\Request request
* @param \Closurenext
* @return mixed
*/
public function handle(request, Closurenext)
{
//return "middleware";
echo "this is checkage middleware";
return next(request);
}}
输出
在中间件中检查条件
中间件也可以用来检查条件。让我们通过一个例子来理解。
Route::Get('/{age}',function($age)
{
return view('welcome');
})-> middleware('age');
<?php
namespace App\Http\Middleware;
use Closure;
class CheckAge
{
/**
* Handle an incoming request.
*
* @param
\Illuminate\Http\Request request
* @param \Closurenext
* @return mixed
*/
public function handle(request, Closurenext)
{
//return "middleware";
if(request->age>10)
{
echo "Age is greater than 10";
}
else
{
echo"Age is not greater than 10";
}
returnnext($request);
}}
输出：
