Enum with a getter

Question

Is an enum able to store references to a getter method, using a Supplier?

To be use like that :

String value = myEnum.getValue(object)

I can't figure how to write it without compiling errors.

Answer 1

If I get you right then you want to do something like this:

import java.util.function.DoubleSupplier;

public class Test {

  enum MathConstants {

    PI(Test::getPi), E(Test::getE);

    private final DoubleSupplier supply;

    private MathConstants(DoubleSupplier supply) {
      this.supply = supply;
    }

    public double getValue() {
      return supply.getAsDouble();
    }
  }

  public static void main(String... args) {
    System.out.println(MathConstants.PI.getValue());
  }

  public static double getPi() {
    return Math.PI;
  }

  public static double getE() {
    return Math.E;
  }
}