laravel实现前后台路由分离的方法

<?php
 
namespace App\Providers;
 
use Illuminate\Routing\Router;
use Illuminate\Foundation\Support\Providers\RouteServiceProvider as ServiceProvider;
 
class RouteServiceProvider extends ServiceProvider
{
 /**
 * This namespace is applied to the controller routes in your routes file.
 *
 * In addition, it is set as the URL generator's root namespace.
 *
 * @var string
 */
 protected $namespace = 'App\Http\Controllers';
 protected $backendNamespace;
 protected $frontendNamespace;
 protected $apiNamespace;
 protected $currentDomain;
 
 /**
 * Define your route model bindings, pattern filters, etc.
 *
 * @param \Illuminate\Routing\Router $router
 * @return void
 */
 public function boot(Router $router)
 {
 //
 $this- backendNamespace = 'App\Http\Controllers\Backend';
 $this- frontendNamespace = 'App\Http\Controllers\Frontend';
 $this- apiNamespace = 'App\Http\Controllers\API';
// $this- currentDomain = $this- app- request- server- get('HTTP_HOST');
 $this- currentDomain = isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : "";
 
 parent::boot($router);
 }
 
 /**
 * Define the routes for the application.
 *
 * @param \Illuminate\Routing\Router $router
 * @return void
 */
 public function map(Router $router)
 {
// $router- group(['namespace' =  $this- namespace], function ($router) {
//  require app_path('Http/routes.php');
// });
 
 $backendUrl = config('route.backend_url');
 $frontendUrl = config('route.frontend_url');
 $apiUrl = config('route.api_url');
 
 switch ($this- currentDomain) {
  case $apiUrl:
  // API路由
  $router- group([
   'domain' =  $apiUrl,
   'namespace' =  $this- apiNamespace],
   function ($router) {
   require app_path('Http/routes-api.php');
   }
  );
 
  break;
  case $backendUrl:
  // 后端路由
  $router- group([
   'domain' =  $backendUrl,
   'namespace' =  $this- backendNamespace],
   function ($router) {
   require app_path('Http/routes-backend.php');
   }
  );
  break;
  default:
  // 前端路由
  $router- group([
   'domain' =  $frontendUrl,
   'namespace' =  $this- frontendNamespace],
   function ($router) {
   require app_path('Http/routes-frontend.php');
   }
  );
 
  break;
 }
 
 }
}