Laravel 5.2 appear weird : Method [validateNickName] does not exist

Version:Laravel 5.2

issue:

BadMethodCallException in Validator.php line 3295:
Method [validateNickName] does not exist.
in Validator.php line 3295
at Validator->__call('validateNickName', array('nick_name', 'chenmin', array(), object(Validator))) in Validator.php line 485
at Validator->validateNickName('nick_name', 'chenmin', array(), object(Validator)) in Validator.php line 485
at Validator->validate('nick_name', 'nick_name') in Validator.php line 425
at Validator->passes() in Validator.php line 450
at Validator->fails() in ValidatesRequests.php line 53
at Controller->validate(object(Request), array('nick_name' => 'required|nick_name|unique:users|max:30', 'cellphone' => 'required|cellphone|unique:users|numeric|phone_number|size:11', 'captcha' => 'required|numeric|size:6', 'password' => 'required|min:6|max:30')) in UserController.php line 19
at UserController->postSignUp(object(Request))
at call_user_func_array(array(object(UserController), 'postSignUp'), array(object(Request))) in Controller.php line 80
at Controller->callAction('postSignUp', array(object(Request))) in ControllerDispatcher.php line 146
at ControllerDispatcher->call(object(UserController), object(Route), 'postSignUp') in ControllerDispatcher.php line 94
at ControllerDispatcher->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103
at Pipeline->then(object(Closure)) in ControllerDispatcher.php line 96
at ControllerDispatcher->callWithinStack(object(UserController), object(Route), object(Request), 'postSignUp') in ControllerDispatcher.php line 54
at ControllerDispatcher->dispatch(object(Route), object(Request), 'App\Http\Controllers\UserController', 'postSignUp') in Route.php line 174
at Route->runController(object(Request)) in Route.php line 140
at Route->run(object(Request)) in Router.php line 724
at Router->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in VerifyCsrfToken.php line 64
at VerifyCsrfToken->handle(object(Request), object(Closure))
at call_user_func_array(array(object(VerifyCsrfToken), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in ShareErrorsFromSession.php line 49
at ShareErrorsFromSession->handle(object(Request), object(Closure))
at call_user_func_array(array(object(ShareErrorsFromSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in StartSession.php line 64
at StartSession->handle(object(Request), object(Closure))
at call_user_func_array(array(object(StartSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in AddQueuedCookiesToResponse.php line 37
at AddQueuedCookiesToResponse->handle(object(Request), object(Closure))
at call_user_func_array(array(object(AddQueuedCookiesToResponse), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in EncryptCookies.php line 59
at EncryptCookies->handle(object(Request), object(Closure))
at call_user_func_array(array(object(EncryptCookies), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103
at Pipeline->then(object(Closure)) in Router.php line 726
at Router->runRouteWithinStack(object(Route), object(Request)) in Router.php line 699
at Router->dispatchToRoute(object(Request)) in Router.php line 675
at Router->dispatch(object(Request)) in Kernel.php line 246
at Kernel->Illuminate\Foundation\Http\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in CheckForMaintenanceMode.php line 44
at CheckForMaintenanceMode->handle(object(Request), object(Closure))
at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 103
at Pipeline->then(object(Closure)) in Kernel.php line 132
at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 99
at Kernel->handle(object(Request)) in index.php line 54

source code:

namespace App\Http\Controllers;
use App\User;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;

class UserController extends Controller
{   
    public function postSignUp(Request $request)
    {
        $this->validate($request, [
                'nick_name' => 'required|nick_name|unique:users|max:30',
                'cellphone' => 'required|cellphone|unique:users|numeric|phone_number|size:11',
                'captcha'   => 'required|numeric|size:6',           
                'password'  => 'required|min:6|max:30'

        ]);
.......

when I test the input from ,met a weird issue:BadMethodCallException in Validator.php line 3295:Method [validateNickName] does not exist.

who can help me to solve it ?thanks a lot!

via Chebli Mohamed