Executing action depending on enum value

Question

I'm trying to retrieving a value depending on the enum value. Basically, let's say I have the following enum:

    private enum Auth{

    KEY, PASSWORD, MAIL;    

    public String get(){
        return "";
    }
}

By doing Auth.KEY.get() it would return "mykey", while Auth.MAIL.get() would return "mymail" I googled a bit but I couldn't find an answer, I didn't try anything before because I totally hadn't an idea on how I could start.

Just google for "Java enum tutorial", click on the first link, and read. — JB Nizet, Mar 11 '17 at 09:11
enums can have a constructor and its own fields.... consider that too please — ΦXocę 웃 Пepeúpa ツ, Mar 11 '17 at 09:12
Possible duplicate of [Can I add a function to enums in Java?](http://stackoverflow.com/questions/2457076/can-i-add-a-function-to-enums-in-java) — m7913d, Mar 11 '17 at 09:13
@RubenOktay you can do it with an abstract method overridden in each enum, or your get() method could use a switch statement to test the value of `this`, but a field and a constructor is way simpler. Why wouldn't you use that? — JB Nizet, Mar 11 '17 at 09:19
Well, i cannot use a constructor as the string will be updated often.. — , Mar 11 '17 at 09:23
That's probably a bad idea, but anyway, I don't see how that prevents you from using a constructor. To the contrary. If the string s updated, you *need* a field to contain the new value, and you thus need a constructor to initialize the field. — JB Nizet, Mar 11 '17 at 09:25

score 1 · Answer 1 · edited May 23 '17 at 11:46

Just add a field and constructor, as explained in the java-docs

Example code:

enum Auth {

    KEY("myKey"), PASSWORD("myPass"), MAIL("myMail");    

    private final String identifier;

    Auth(String identifier) {
        this.identifier = identifier;
    }

    public String get(){
        return identifier;
    }
}

Also note, that there is name() and toString() which may be useful: see also java-enum-why-use-tostring-instead-of-name

score 0 · Answer 2 · answered Mar 11 '17 at 09:13

0

enum Auth{
private enum Auth{
String value;
KEY("mykey"), PASSWORD("mypassword"),    MAIL(mymail");    

Auth(String value){
thia.value=value;
}
public String get(){
    return value;
}
}

answered Mar 11 '17 at 09:13

Jayanand Raghuwanshi

499
3
12

score 0 · Answer 3 · answered Mar 11 '17 at 09:13

You need to have a string which holds the name of of enum and a constructor which sets it. Then get method returns the name as below.

 private enum Auth{

    KEY, PASSWORD, MAIL;    
    string name;
    public Auth(string nm) {
      name = nm;
    }
    public String get(){
        return name;
    }
 }

score 0 · Accepted Answer · answered Mar 11 '17 at 19:42

Although I strongly advise not to use the following mechanism for getting something simple like a hardcoded String from an enum value and rather use it for associating particular behavior like in java.util.concurrent.TimeUnit, this is how it can be achieved:

private enum Auth {

    KEY {
        public String get() {
            return "mykey";
        } 
    },

    PASSWORD {
        public String get() {
            return "mypassword";
        } 
    },

    MAIL {
        public String get() {
            return "mymail";
        } 
    };

    public abstract String get();

}

Executing action depending on enum value

4 Answers4