Shopware 5 methods alternative in Shopware 6

Shopware 6 (English)
1

Hi , i working on upgrading module from shopware 5 to shopware 6 . what will be the best alternative to the following shopware 5 methods in shopware 6.

Shopware()->Config()->getByNamespace('Plugin-name', 'i-think-configname');
Shopware()->Db()->fetchRow

i want to call these methods in service that i have created .i am using service in admin controller