Spring Framework is the most popular and used MVC (Model View Controller) Framework for developing Web Applications in java .It is widely used by many developers and companies . Before spring 3 , spring used to be configured using XML. But , since Spring 3 , Java Config has been allowed to ease the configuration process for developers . But , XML is also allowed if you prefer .It is totally on you how you want to configure .Spring is rising day by day changing the face of Java Enterprise Development (Java EE) .
As you are already familiar with Java , it is very easier to configure with Java than with XML . I personally like java config but you can still use XML if you love XML .