A java class only with "private final static" variables.. Is it a good idea?

Question

I just want to know, since I have a lot of private final static variables in my 3 classes, if It is a good idea to put them in just one classe like this :

public class Definicoes 
{
    /*
    * Definições da Janela de Jogo
    */

    public final static String nomeJanela;
    public final static short janLargura;
    public final static short janAltura;
    public final static byte tabLinhas;
    public final static byte tabColunas;
    static
    {
    nomeJanela = "JFindPairs - 0.3";
    janLargura = 480;
    janAltura = 480;
    tabLinhas = 4;
    tabColunas = 4;
    }

    /*
    * Definições do Tabuleiro e respectivas Cartas
    */

    public final static byte numeroCartoes;
    static
    {
        numeroCartoes = 16;
    }
}

Thanks in Advance for any help. Luis Da Costa

Your subject line says "private final static", but the example code shows "public final static". — Paul Tomblin, Apr 29 '12 at 15:56
In the original class I used them as private, but here to access them in the other classes I need them as Public, this is why I ask. If it is a good idea to separate them from the original classes and make them public — aliasbody, Apr 29 '12 at 15:58
Just about terminology: The keyword 'final' violates most common definitions of the word 'variable'. And why do you introduce a static block, and don't just write the assignment to the declaration: `public final static String nomeJanela = "JFindPairs - 0.3";? Are you get paid per line? — user unknown, Apr 29 '12 at 15:59
Those look to be settings for a GUI game. Perhaps this should be stored in a settings file outside of the code, perhaps an XML file, since this seems like set up data that might change. — Hovercraft Full Of Eels, Apr 29 '12 at 15:59
possible duplicate of [What is the best way to implement constants in Java?](http://stackoverflow.com/questions/66066/what-is-the-best-way-to-implement-constants-in-java) — Don Roby, Apr 29 '12 at 15:59
By the way according to the Java Code Conventions `static final` fields should be named with all uppercase letters, numbers, and underscores, e.g. NOME_JANELA. — kapandron, Apr 29 '12 at 16:07

score 4 · Accepted Answer · answered Apr 29 '12 at 15:57

4

I would put them in one place if they all have to be the same. Otherwise, I would keep the constants where they are used.

answered Apr 29 '12 at 15:57

Peter Lawrey

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The last static variable is from another class, this is why they are separated – aliasbody Apr 29 '12 at 16:00
1

This suggests to me they don't need to be all in one place. Its often best to minimise the dependencies between classes. BTW: I would use `final static byte numeroCartoes = 16;` – Peter Lawrey Apr 29 '12 at 16:03
what would be the diference ? – aliasbody Apr 29 '12 at 16:07
Its about maintainability. Sometimes keeping your constants in one place is the easiest, but more often the constants don't change and having to hunt around to find where a value is set is more difficult. – Peter Lawrey Apr 29 '12 at 16:09
Seems like this is really set up data and not constant information, that this should be retrieved from a file. – Hovercraft Full Of Eels Apr 29 '12 at 16:36
1

@HovercraftFullOfEels Agreed, changeable data should really come from an external file like a Properties. – Peter Lawrey Apr 29 '12 at 16:38

score 1 · Answer 2 · answered Apr 29 '12 at 15:56

1

that's how I do it, It makes sense to have them all in 1 place in case you need to come back and change them at some point in time, don't want to have to search loads of classes for 1 variable :)

answered Apr 29 '12 at 15:56

Skyste

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4

score 1 · Answer 3 · answered Apr 29 '12 at 15:56

When they start as private i.e. they are used only in a single class, they should stay there.

If they need to get accessed by different classes there is probably some concept hiding. The concept might manifest itself as a class with just public static final variables, but more likely it will split in multiple classes (at least that is my experience). Unfortunatly there is now way to tell with out knowing more about your program.

score 1 · Answer 4 · answered Apr 29 '12 at 16:00

1

It's completely valid to do so however it would break the concept of OOP design to decouple variables / constants that belong to a specific class.

answered Apr 29 '12 at 16:00

Will Kru

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A java class only with "private final static" variables.. Is it a good idea?

4 Answers4