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having a little architectural trouble here.
In C++, we have the notion of 'friends,' where such friend classes can access private members.
So, I'm deving a Java app and trying to adhere to the MVC architecture. I've got a controller class that manages graph connectivity between 'map_objects.' I'd like to hide the function in the DTO 'map_objects' that actuall sets up these connectivities, by using this controller class.
(Ie, even if the controller class implements the required functionality of setting up connectivities, the 'users' can still access setter/getter functions in the the DTO directly to set them up themselves.)
Are there any design patterns or tips in this regard? (Or have I totally mucked up?)
DUPLICATE Is there a way to simulate the C++ 'friend' concept in Java?
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friend function of a class is defined outside that class' scope but it has the right to access all private and protected members of the class. Even though the prototypes for friend functions appear in the class definition, friends are not member functions.
4) The concept of friends is not there in Java.
It's simply wrong. While it's true that friend can be used to break encapsulation, so can other features be misused. Used correctly, friend enhances encapsulation because it enables a more fine-grained access control: friend replaces use of public , not use of private .
In object-oriented programming, a friend function, that is a "friend" of a given class, is a function that is given the same access as methods to private and protected data. A friend function is declared by the class that is granting access, so friend functions are part of the class interface, like methods.
(Un)fortunately, there is no direct C++ friend equivalent in Java. However, the Java access level modifiers can assist you. In particular, private or package private (AKA package protected, or "default") may help.
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