Encapsulating Constants in a Program : Interface « Class Definition « Java Tutorial

interface ConversionFactors {
  double INCH_TO_MM = 25.4;

  double OUNCE_TO_GRAM = 28.349523125;

  double POUND_TO_GRAM = 453.5924;

  double HP_TO_WATT = 745.7;

  double WATT_TO_HP = 1.0 / HP_TO_WATT;
public class MainClass {
  public static void main(String[] a) {

5.29.1.Interfaces and Abstract Classes
5.29.2.Fields and Methods in an Interface
5.29.3.To implement an interface: use the implements keyword after the class declaration
5.29.4.A Partial Interface Implementation
5.29.5.Extending Interfaces
5.29.6.Interfaces and Multiple Inheritance
5.29.7.Interfaces and Polymorphism: Using Multiple Interfaces
5.29.8.Nesting Classes in an Interface Definition
5.29.9.Encapsulating Constants in a Program
5.29.10.Multiple interfaces
5.29.11.Initializing interface fields with non-constant initializers