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.