Constant interface

In the Java programming language, the constant interface anti-pattern describes the use of interfaces to define constants. This would enable classes implementing interface to use the constants as member variables. However, since the usage of constants is considered an implementation detail, it is considered inappropriate to define an interface for this purpose.

Example

public interface Constants {

	public static final double PI = 3.14159;

	public static final double PLANCK_CONSTANT = 6.62606896e-34;

}


public class Calculations implements Constants {

	public double getReducedPlanckConstant() {
		return PLANCK_CONSTANT / (2 * PI);
	}

}