You don't simply model information in an OO language, everything is an object, you're supposed to model your domain. I don't reach into the employee class and

You don't simply model information in an OO language, everything is an object, you're supposed to model your domain. I don't reach into the employee class and "get" the employee ID so I can do something with it. The employee class knows what to do with their own ID. Just like a cashier doesn't reach into a Person's brain for their debit code. The cashier asks them to type it into the keypad, and points them where to do it if it isn't obvious. Low-level accessors to an "object's" state are almost never an accurate representation of the domain you are modeling -- they're bad design. If you need them, you've probably missed a piece of the puzzle. That being said, most programmers don't need to be doing OO at all. The level of guarantee it provides is, for most people, not worth the cost. In those cases, don't use Java. We will all be having this same argument about functional languages in 10 years. Mutability is not functional, if you're relying on mutability you're probably just doing procedural code wrapped up in functional decorations.