(1/1) FatalErrorException Class 'Yajra\DataTables\DataTablesServiceProvider' not found in ProviderRepository.php line 208

I am using laravel 5.4 and php version is 5.6. I am trying to install yajra datatable. For this I installed yajra datatble using composer.

composer require yajra/laravel-datatables-oracle:"~7.0"

I had successfully installed yajra folder in vendor folder. after this I added following lines in config->app.php in providers and aliases.

Yajra\DataTables\DataTablesServiceProvider::class,
'DataTables' => Yajra\DataTables\Facades\DataTables::class,

but when I run that command

php artisan vendor:publish --provider=Yajra\DataTables\DataTablesServiceProvider

I got this error:

(1/1) FatalErrorException Class 'Yajra\DataTables\DataTablesServiceProvider' not found  in ProviderRepository.php line 208

I google it and found I need to update and auto-load composer. I did it but no luck. Any help would be highly appreciable.

via Chebli Mohamed