CODEWITHSUNDEEP
java
yoav.str
yoav.str

Reputation: 1534

what is Java best practice to handle enum's

hi I know Java for a long time and recently I have been diving deep to the Java world. As an experienced c# developer I find it odd to use Java enum's. For example if I show on console items such as :

public enum AdminOpertionFirstlayer 
{MANAGE_SUPPLY,
 MANAGE_CUSTOMERS_SERVICE,
 ORDERS_MANAGEMENT,
 REPORTING_OPRATIONES}

I find it hard to write them down to the user , cause I have to define new varible

*AdminOpertionFirstlayer []adminOpertionFirstlayerArr =
     AdminOpertionFirstlayer.values();

in order to achieve this : 

for (int i = 0; i < adminOpertionFirstlayerArr.length; i++) {
    String s = String.format("%d. %s",
                             i+1,
                             adminOpertionFirstlayerArr[i].toString());
    Screen.print(s);
}

AdminOpertionFirstlayer chosen= adminOpertionFirstlayerArr 
                                [(Integer.parseInt(dataIn.readLine()))-1];

But I feel it's a bad practice to declare on *

  1. Is there a best practice (enum extension is one ... ) ?
  2. Is there TryParse available or every time I parse I should try and catch ?

thank you

EDIT

does doing this is understandable and readable ?

  public enum MainMenuOptiones{

    ADMIN {public void secondLayerMenu(){
      Main.AdminSecondLayerMenu();}},

    CUSTOMER{public void secondLayerMenu(){
       Main.customerSecondLayerMenu();}},

    EXIT{public void secondLayerMenu(){
        System.exit(1);}},

    UNAPPLICABLE{public void secondLayerMenu(){
        Screen.printToScreen("chice doesnt exist  try again");}};

    abstract public void secondLayerMenu();
}

the phrphes is instead of using all the switch mechanism I can use 

 enumInstance.secondLayerMenu();

Upvotes: 1

Views: 2103

Answers (2)

Michael Barker
Michael Barker

Reputation: 14398

You could use Java's enhanced for loop (and the ordinal value for the enum)

for (AdminOperatorFirstLayer operator : AdminOperatorFirstLayer.values()) {
    String s = String.format("%d. %s", operator.ordinal(), operator);
    Screen.print(s);
}

Then you can use the ordinal value to recreate the enum:

AdminOperatorFirstLayer chosen = 
    AdminOperatorFirstLayer.values()[(Integer.parseInt(dataIn.readLine()))];

Or you could use the name:

for (AdminOperatorFirstLayer operator : AdminOperatorFirstLayer.values()) {
    String s = String.format("%s. %s", operator.name(), operator);
    Screen.print(s);
}

Then you can use valueOf value to recreate the enum:

AdminOperatorFirstLayer chosen = 
    AdminOperatorFirstLayer.valueOf(dataIn.readLine()];

Upvotes: 5

Pete Kirkham
Pete Kirkham

Reputation: 49331

The Enum<E> class is the base for all enums in Java.

There's no need to declare a variable with values, use an enhanced for loop to print them out if you want the users to read your source code.

Generally you want to print out a localised string rather than the name of the enum in the source.

There isn't an equivalent to TryParse, instead use AdminOpertionFirstlayer.valueOf(AdminOpertionFirstlayer.class, string) and catch the IllegalArgumentException.

Upvotes: 1

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