I am writing a set of junit test classes in java. There are several constants, for example strings that I will need in different test classes. I am thinking about an interface that defines them and every test class would implement it. The benefits I see there are: easy access to constants: "MY_CONSTANT" instead of "ThatClass.MY_CONSTANT" each constant defined only once Is this approach rather a good or bad practice? I feel like abusing the concept of interfaces a little bit. You can answer generally about interfaces/constants, but also about unit tests if there is something special about it.