Java 的“朋友”等价物？
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'Friends' equivalent for Java?
提问by Alex Lim
having a little architectural trouble here.
这里有一点架构问题。
In C++, we have the notion of 'friends,' where such friend classes can access private members.
在 C++ 中，我们有“朋友”的概念，这样的朋友类可以访问私有成员。
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.
所以，我正在开发一个 Java 应用程序并尝试遵守 MVC 架构。我有一个控制器类，用于管理“map_objects”之间的图形连接。我想通过使用这个控制器类隐藏实际设置这些连接的 DTO 'map_objects' 中的函数。
(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.)
（即，即使控制器类实现了设置连接所需的功能，“用户”仍然可以直接访问 DTO 中的 setter/getter 函数以自行设置它们。）
Are there any design patterns or tips in this regard? (Or have I totally mucked up?)
在这方面是否有任何设计模式或提示？（还是我完全搞砸了？）
DUPLICATEIs there a way to simulate the C++ 'friend' concept in Java?
DUPLICATE有没有办法在 Java 中模拟 C++“朋友”概念？
采纳答案by Julien Chastang
(Un)fortunately, there is no direct C++ friend equivalent in Java. However, the Java access level modifierscan assist you. In particular, private or package private (AKA package protected, or "default") may help.
（不）幸运的是，Java 中没有直接的 C++ 朋友等价物。但是，Java 访问级别修饰符可以为您提供帮助。特别是，私有或包私有（AKA 包保护，或“默认”）可能会有所帮助。
回答by Ilja Preu?
You might want to use interface segregation- that is, let the class implement different interfaces, and only pass out references to the appropriate (smaller) interfaces to the different clients.
您可能想要使用接口隔离——也就是说，让类实现不同的接口，并且只向不同的客户端传递对适当（较小）接口的引用。
