本篇文章给大家带来的内容是关于Laravel API跨域访问的实现步骤，有一定的参考价值，有需要的朋友可以参考一下，希望对你有所帮助。
服务器A请求服务器B的接口，那么一般会出现跨域问题。
XMLHttpRequest cannot load http://api.console.vms3.com/api/user. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8080' istherefore not allowed access.
意思就是服务器响应不允许跨域访问.
那我们就需要让服务器支持跨域访问, 也就是在响应头部中添加
'Access-Control-Allow-Origin: *'
第一步: 创建中间件
创建 `app/Http/Middleware/AccessControlAllowOrigin.php` middleware 把 'Access-Control-Allow-Origin: *' 写入头部.app/Http/Middleware/AccessControlAllowOrigin.php<?phpnamespace AppHttpMiddleware;use Closure;use IlluminateSupportFacadesAuth;class AccessControlAllowOrigin{ /** * * Handle an incoming request. * * @param IlluminateHttpRequest $request * @param Closure $next * @return mixed */ public function handle($request, Closure $next) { header('Access-Control-Allow-Origin: *'); header("Access-Control-Allow-Credentials: true"); header("Access-Control-Allow-Methods: *"); header("Access-Control-Allow-Headers: Content-Type,Access-Token"); header("Access-Control-Expose-Headers: *"); return $next($request); }}第二步: 注册路由
注册这个 middleware 到 kernel 中.
分别在 protected $middleware 数组中和 protected $routeMiddleware 数组中
添加我们刚才创建的那个文件class名, 使用 cors 这个别名.
第三步: 设置中间件保护接口
然后在设置它保护 api , 就是$middlewareGroups['api'] 的数组中添加它的别名, 本文中是 'cors'app/Http/Kernel.php
<?phpnamespace AppHttp;use IlluminateFoundationHttpKernel 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 = [ IlluminateFoundationHttpMiddlewareCheckForMaintenanceMode::class, IlluminateFoundationHttpMiddlewareValidatePostSize::class, AppHttpMiddlewareTrimStrings::class, IlluminateFoundationHttpMiddlewareConvertEmptyStringsToNull::class, AppHttpMiddlewareAccessControlAllowOrigin::class, ]; /** * The application's route middleware groups. * * @var array */ protected $middlewareGroups = [ 'web' => [ AppHttpMiddlewareEncryptCookies::class, IlluminateCookieMiddlewareAddQueuedCookiesToResponse::class, IlluminateSessionMiddlewareStartSession::class, // IlluminateSessionMiddlewareAuthenticateSession::class, IlluminateViewMiddlewareShareErrorsFromSession::class, AppHttpMiddlewareVerifyCsrfToken::class, IlluminateRoutingMiddlewareSubstituteBindings::class, ], 'api' => [ 'throttle:60,1', 'bindings', 'cors' ], ]; /** * The application's route middleware. * * These middleware may be assigned to groups or used inpidually. * * @var array */ protected $routeMiddleware = [ 'auth' => IlluminateAuthMiddlewareAuthenticate::class, 'auth.basic' => IlluminateAuthMiddlewareAuthenticateWithBasicAuth::class, 'bindings' => IlluminateRoutingMiddlewareSubstituteBindings::class, 'can' => IlluminateAuthMiddlewareAuthorize::class, 'guest' => AppHttpMiddlewareRedirectIfAuthenticated::class, 'throttle' => IlluminateRoutingMiddlewareThrottleRequests::class, 'cors' => AppHttpMiddlewareAccessControlAllowOrigin::class, ];}第四步：在路由中添加路由
Route::middleware('cors')->group(function () { //});
