I study java se & ee, 1/2 year now [selfstudy + the 4 diplomas from javaonline.org], well I covered oop and EE material incl DBs... When a java programmer can start with Spring? I can start with ease? all or some features?
You can start with some partst. Auto-wiring beans and dependency injection are easy to grasp. Other parts require more advanced knowledge. You need to know about design patterns and advanced technologies to appreciate some parts. While there's no harm in learning the basics of Spring, I would learn more about Java first.