Pass Enum value per method parameter

Question

I have a value that stores the status of an element. For example: 1 - sending 2 - Cancelled 3 - Error.

The value that will be saved in the database is the numeric value. I have a method that sets the status, but its parameter is of the numeric type.

The fact is that I didn’t want to have to pass the value on itself, but I wanted to pass using enum.

setStatus (Status.CANCELADA);

public enum Status {
     A_ENVIAR(1L), CANCELADA(2L), ERRO(3L);
    
     private Long numVal;
    
     Status(Long numVal) {
         this.numVal = numVal;
     }
    
     public Long getNumVal() {
         return numVal;
     }
}

But to take the numerical value that each enum represent, I’m having to do Status.CANCELADA.getNumVal().

Is there any way I can get the value "2" without calling the method getNumVal()? I want the value 2 calling only Status.CANCELADA.

Answer 1

Why don’t you use the method ordinal() that all enum has? Stay like this:

class Program {
    public static void main (String[] args) {
        Status status = Status.Cancelada;
        System.out.println(status.ordinal());
    }
}

enum Status {
    None, AEnviar, Cancelada, Erro;
}

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.

I gave an improved on this code and without using this nonsense that they taught to write everything in Caps (can do it your way too, but it is very ugly, need to create the constructor, then either use ready method or own).

Answer 2

There’s no way to do that. Because, if it were possible, you could do something like:

Status.CANCELADA == 2L; // ???

And that should be evaluated for what? true? false? Like the Runtime would be able to distinguish when should return the Long (representation of values in the example) or Status (the type of the enumeration in question)?

The previous expression is not even executed - an error is thrown on account of the incompatible types:

Main.java:XX: error: bad operand types for binary operator '=='
    x == 1L;
      ^
  first type:  Status
  second type: long

Therefore, it is ideal to create a way to expose the value of the property. In this case, you are already doing this by the method getNumVal.

Answer 3

galley!

I just had to think for a while, I was thinking of an unnecessary solution.

Define in the class itself the constants with their respective values in a public and static way.

public static final int A_ENVIAR = 1;

So I just called

setStatus(ClasseEmQuestao.A_ENVIAR);