laravel控制器负责错误500

Question

I have been trying to complete an ajax request. However the form submission is giving me error 500. I created a controller to process the form submission. at first i thought the problem was due to _token. But i added token and problem was not fixed. Then i changed my post route and processed the request on the route page and this seems to work. I still want to use a controller to process the form submission.

Routes

    //this does not
    Route::post('/mail',[ 
    'uses'=>'ContactController@postContact',
    'as'=>'postContact'
    ]);
    //this works
    Route::post('/mail2',function(){
    return response()->json([
        'result'=>'success'
    ]);
  });

Problem controller

    <?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Http\Requests;
use App\ContactModel;
class ContactController extends Controller
{
    public function getContactList()
    {
        $contacts = Contact::all();
        return response()->json([
            'contacts'=>$contacts
        ]);
    }
    public function postContact(Requests $request)
    {
        return response()->json([
            'result'=>'success'
        ]);
    }
}

Any idea whats going on?

Fixed: It was a typo guys.

        public function postContact(Request $request)
    {
        return response()->json([
            'result'=>'success'
        ]);
    }