CODEWITHSUNDEEP
javaenums
Andrew Latham
Andrew Latham

Reputation: 6132

Using a method to create enum values

I have an enum: public enum X implements Y

I also have a class Ybuilder which can create instances of Y, let's say with Ybuilder.create(int value)

How can I set the enum values in my enum to be instances of Y created with Ybuilder? ideally it would be something simple like

public enum X implements Y {
  A (Ybuilder.create(0)),
  B (Ybuilder.create(1)),
};

Upvotes: 1

Views: 68

Answers (1)

assylias
assylias

Reputation: 328775

I don't think you can do it that way - one alternative would be to delegate to the Y instance created by the builder. For example:

interface Y { //Assume Y has two methods
   void m1();
   void m2();
}

public enum X implements Y {
  A (0),
  B (1);
  private final Y y;
  X(int value) { this.y = YBuilder.create(value); }

  //Then delegate to y to implement the Y interface

  public void m1() { y.m1(); return; }
  public void m2() { y.m2(); return; }
};

Note that I created the enums with the int argument but you can pass a Y directly if you prefer:

public enum X implements Y {
  A (Ybuilder.create(0)),
  B (Ybuilder.create(1));
  private final Y y;
  X(Y y) { this.y = y; }
};

Upvotes: 6

Related Questions