How do you define a class of constants in Java?

Question

Suppose you need to define a class which all it does is hold constants.

public static final String SOME_CONST = \"SOME_VALUE\";

What is the

Answer 1

1. One of the disadvantage of private constructor is the exists of method could never be tested.

2. Enum by the nature concept good to apply in specific domain type, apply it to decentralized constants looks not good enough

The concept of Enum is "Enumerations are sets of closely related items".

3. Extend/implement a constant interface is a bad practice, it is hard to think about requirement to extend a immutable constant instead of referring to it directly.

4. If apply quality tool like SonarSource, there are rules force developer to drop constant interface, this is a awkward thing as a lot of projects enjoy the constant interface and rarely to see "extend" things happen on constant interfaces