Java interface static method workaround?

Question

We have a given REST interface:

POST /calculation
abc

This calculation can be implemented by different logical \"c

Answer 1

If none of classes implementing this interface does not need to change the implementation, use static method in interface as helper method.

You won't need any workaround with java 8 version.

Java 8 supports static methods in interface. Have a look at this documentation page.

Static Methods:

In addition to default methods, you can define static methods in interfaces. (A static method is a method that is associated with the class in which it is defined rather than with any object. Every instance of the class shares its static methods.)

This makes it easier for you to organize helper methods in your libraries; you can keep static methods specific to an interface in the same interface rather than in a separate class

Other solution to your problem is using Singleton as suggested in accepted answer.