测试RESTfulAPI（流明）http/https协议是问题吗？

我正在关注本教程https://www.youtube.com/watch?v=6Oxfb_HNY0U
建立一个小的流明测试项目。
我目前在第27分钟，您应该通过发帖请求插入一条记录。
为此，我正在使用RESTClient http://restclient.net/

所以，在最后一天，我已经尽力解决了这个问题，而且由于这样，我也至少可以
部分解决问题：
What does the second paremeter in "json()" do (Lumen/Laravel)?

但是，我仍然收到错误而不是新记录。
向...发送帖子请求时

http://localhost:8080/api/articles


我收到此错误：

(1/1) BadMethodCallException
Method Laravel\Lumen\Http\Request::validate does not exist.
in Macroable.php line 103
at Request->__call('validate',array(array('title' => 'required','description' => 'required')))in ArticleController.php line 36
at ArticleController->create(object(Request))
at call_user_func_array(array(object(ArticleController),'create'),array(object(Request)))in BoundMethod.php line 32
at BoundMethod::Illuminate\Container\{closure}()in Util.php line 34
at Util::unwrapIfClosure(object(Closure))in BoundMethod.php line 90
at BoundMethod::callBoundMethod(object(Application),array(object(ArticleController),object(Closure))in BoundMethod.php line 34
at BoundMethod::call(object(Application),array(),null)in Container.php line 590
at Container->call(array(object(ArticleController),array())in RoutesRequests.php line 376
at Application->callControllerCallable(array(object(ArticleController),array())in RoutesRequests.php line 342
at Application->callLumenController(object(ArticleController),'create',array(true,array('uses' => 'App\\Http\\Controllers\\ArticleController@create'),array()))in RoutesRequests.php line 316
at Application->callControlleraction(array(true,array()))in RoutesRequests.php line 278
at Application->callactionOnArrayBasedRoute(array(true,array()))in RoutesRequests.php line 263
at Application->handleFoundRoute(array(true,array()))in RoutesRequests.php line 165
at Application->Laravel\Lumen\Concerns\{closure}(object(Request))in RoutesRequests.php line 416
at Application->sendThroughPipeline(array(),object(Closure))in RoutesRequests.php line 171
at Application->dispatch(null)in RoutesRequests.php line 108
at Application->run()in index.php line 28


由于我是Lumen / Laravel的新手，所以我很难从该错误中猜测任何东西。
我不知道我是否拼错了什么，没有注意范围或诸如此类。

现在，这是产生此错误的代码：
web.php（路线），Article.php（模型，位于应用程序文件夹中）和ArticleController.php（控制器）：

web.php：

/*
|--------------------------------------------------------------------------
| Application Routes
|--------------------------------------------------------------------------
|
| Here is where you can register all of the routes for an application.
| It is a breeze. Simply tell Lumen the URIs it should respond to
| and give it the Closure to call when that URI is requested.
|
*/
$router->get('/',function () use ($router) {
return $router->app->version();
});
// was simply 'api' in tutorial
$router->group(['prefix' => '/api'],function($router){
$router->get('articles','ArticleController@showAllArticles');
$router->get('articles/{id}','ArticleController@showOneArticle');
$router->post('articles','ArticleController@create');
});


ArticleController.php

namespace App\Http\Controllers;
use App\Article;
use Illuminate\Http\Request;
class ArticleController extends Controller
{
/**
* Create a new controller instance.
*
* @return void
*/
public function __construct()
{
//
}
//
public function showAllArticles(){
return response()->json(Article::get(['title','description','status'])); // ::get([]) spezifiziert die zu referenzierenden Attribute
// ::all() referenziert alle Attribute einer Tabelle/Relation
}
public function showOneArticle($id){
return response()->json(Article::find($id));
}
public function create(Request $request){
//dd($request); //for debugging whether the request is actually being processed
$validatedData = $request->validate([
'title' => 'required','description' => 'required',]);
//dd($request); //for debugging whether the specified fields are required
//insert record
$article = Article::create($request->all());
return response()->json($article,201);
}
}


Article.php：

namespace App;
use Illuminate\Database\Eloquent\Model;
class Article extends Model
{
protected $fillable = [
'title','status'
];
}


由于与教程代码相比修改了此代码中的函数“ create（）”（请参阅​​顶部引用的SO问题中的ege答案），因此我也尝试了教程代码，其中create（ ）函数如下所示：

public function create(Request $request){
$this->validation($request,[
'title' => 'required','description' => 'required'
]);
$article = Article::create($request->all());
return response()->json($article,201);
}


在这种情况下，我得到另一个错误：

(1/1) Error
Call to undefined method App\Http\Controllers\ArticleController::validation()
in ArticleController.php line 41
at ArticleController->create(object(Request))
at call_user_func_array(array(object(ArticleController),object(Closure))in RoutesRequests.php line 171
at Application->dispatch(null)in RoutesRequests.php line 108
at Application->run()in index.php line 28


与第一个错误相比，我在理解错误方面基本上存在相同的问题。
我在这里查看了流明文档：
https://lumen.laravel.com/docs/6.x/validation

我又想知道我是否不正确地理解范围（“ this”在这里指的是什么，它是什么对象，实际上可以从中调用什么方法？）。

为了完整起见，我用雄辩的模型“ Article”引用的表的屏幕截图：
https://imgur.com/onXEgzg

总的来说，我真是一无所知，如果有人可以“帮我搭便车”，我将非常感激^^

查看修改后的示例（create()方法的第二版），错误的第一行显示了问题：

  

调用未定义的方法App \ Http \ Controllers \ ArticleController :: validation（）

代码中的这一行有问题：

$this->validation() ...


检查the link to the Lumen docs是否包含：

  

在流明中可用的$ this-> validate助手...

因此有一个validate()助手-但是您正在使用validation()。