Java Enum return Int

Question

I'm having trouble declaring an enum. What I'm trying to create is an enum for a 'DownloadType', where there are 3 download types (AUDIO, VIDEO, AUDIO_AND_VIDEO).

I have implemented the code as follows:

private enum DownloadType {     AUDIO(0), VIDEO(1), AUDIO_AND_VIDEO(2);     private final int value;      private DownloadType(int value) {         this.value = value;     } } 

This works fine if I then use it like this:

DownloadType.AUDIO_AND_VIDEO.value; 

However, I would like it so that I don't have to ask for the 'value'. I may be mistaken, but this is the way several classes work in Java such as Font, for example to set a font style, you use:

Font.PLAIN 

Which returns an int value, we don't use:

Font.PLAIN.value 

Answer 1

Font.PLAIN is not an enum. It is just an int. If you need to take the value out of an enum, you can't avoid calling a method or using a .value, because enums are actually objects of its own type, not primitives.

If you truly only need an int, and you are already to accept that type-safety is lost the user may pass invalid values to your API, you may define those constants as int also:

public final class DownloadType {     public static final int AUDIO = 0;     public static final int VIDEO = 1;     public static final int AUDIO_AND_VIDEO = 2;      // If you have only static members and want to simulate a static     // class in Java, then you can make the constructor private.     private DownloadType() {} } 

By the way, the value field is actually redundant because there is also an .ordinal() method, so you could define the enum as:

enum DownloadType { AUDIO, VIDEO, AUDIO_AND_VIDEO } 

and get the "value" using

DownloadType.AUDIO_AND_VIDEO.ordinal() 

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Edit: Corrected the code.. static class is not allowed in Java. See this SO answer with explanation and details on how to define static classes in Java.

Answer 2

If you need to get the int value, just have a getter for the value in your ENUM:

private enum DownloadType {     AUDIO(1), VIDEO(2), AUDIO_AND_VIDEO(3);     private final int value;      private DownloadType(int value) {         this.value = value;     }      public int getValue() {         return value;     } }  public static void main(String[] args) {     System.out.println(DownloadType.AUDIO.getValue());           //returns 1     System.out.println(DownloadType.VIDEO.getValue());           //returns 2     System.out.println(DownloadType.AUDIO_AND_VIDEO.getValue()); //returns 3 } 

Or you could simple use the ordinal() method, which would return the position of the enum constant in the enum.

private enum DownloadType {     AUDIO(0), VIDEO(1), AUDIO_AND_VIDEO(2);     //rest of the code }  System.out.println(DownloadType.AUDIO.ordinal());            //returns 0 System.out.println(DownloadType.VIDEO.ordinal());            //returns 1 System.out.println(DownloadType.AUDIO_AND_VIDEO.ordinal()); //returns 2