接口与单例中的全局变量
Global variables in Interface vs Singleton
我需要几个全局变量（例如：数据库名称），它们将在我的程序中被其他 classes 使用。
我可以创建一个包含变量的单例 class，但我发现我也可以简单地创建一个包含变量的接口（没有任何方法）。由于接口中的变量是静态的和最终的，这似乎是一个干净的实现。
我读到认为在接口中声明变量是糟糕的设计，那么为什么会这样？创建全局变量的最佳方法是什么？
根据 Sonar rule:
，仅使用接口来保存常量是一种代码味道
Constants should not be defined in interfaces (squid:S1214)
According to Joshua Bloch, author of "Effective Java":
The constant interface pattern is a poor use of interfaces.
That a class uses some constants internally is an implementation detail.
Implementing a constant interface causes this implementation detail to leak into the class's exported API. It is of no consequence to the users of a class that the class implements a constant interface. In fact, it may even confuse them. Worse, it represents a commitment: if in a future release the class is modified so that it no longer needs to use the constants, it still must implement the interface to ensure binary compatibility. If a nonfinal class implements a constant interface,
all of its subclasses will have their namespaces polluted by the constants in the interface.
我需要几个全局变量（例如：数据库名称），它们将在我的程序中被其他 classes 使用。
我可以创建一个包含变量的单例 class，但我发现我也可以简单地创建一个包含变量的接口（没有任何方法）。由于接口中的变量是静态的和最终的，这似乎是一个干净的实现。
我读到认为在接口中声明变量是糟糕的设计，那么为什么会这样？创建全局变量的最佳方法是什么？
根据 Sonar rule:
，仅使用接口来保存常量是一种代码味道Constants should not be defined in interfaces (squid:S1214)
According to Joshua Bloch, author of "Effective Java": The constant interface pattern is a poor use of interfaces.
That a class uses some constants internally is an implementation detail.
Implementing a constant interface causes this implementation detail to leak into the class's exported API. It is of no consequence to the users of a class that the class implements a constant interface. In fact, it may even confuse them. Worse, it represents a commitment: if in a future release the class is modified so that it no longer needs to use the constants, it still must implement the interface to ensure binary compatibility. If a nonfinal class implements a constant interface,
all of its subclasses will have their namespaces polluted by the constants in the interface.