What is the better way of publishing global constants in Java?

问题

Which one of these ways of publishing global constants is better? THANKS!!!

Method 1: final class with public static final fields

public final class CNST{
    private CNST(){}
    public static final String C1;
    public static final String C2;
    static{
       C1="STRING1";
       C2="STRING2";
    }
}
//so I could call C1, C2 like:
//...some code...
//System.out.println(CNST.C1);
//System.out.println(CNST.C2);

Method 2: singleton with enum

public enum CNST{
    INST;
    public final String C1;
    public final String C2;
    CNST{
       C1="STRING1";
       C2="STRING2";
    }
}
//so I could call C1, C2 like:
//...some code...
//System.out.println(CNST.INST.C1);
//System.out.println(CNST.INST.C2);

回答1:

Something that follows more usual conventions would be like this:

public class MyAppConstants {
    public static final String C1 = "STRING1";
    public static final String C2 = "STRING2";
}

Then you can refer to it later like this:

System.out.println(MyAppConstants.C1);

But if I had to pick between the two you give I guess I would choose the first, because the enum is misleading and doesn't help functionally and doesn't make the code clearer.

回答2:

for fans of short'n'sweet code like me, who like to minimize number of characters in code, if you wanna not have the need to pre-pend the constant name with a class name like "MyGlobaConstants", you can create a base activity class, like MyBaseActivity, and extend all your activities from it. As such:

public abstract class MyBaseActivity extends Activity {

   public static final String SOME_GLOBAL_STRING = "some string";
   public static final int SOME_GLOBAL_INT = 360;

Doing this has other benefits as well, such as creating methods that all your activities can use, and is generally a good practice.

来源：https://stackoverflow.com/questions/18169614/what-is-the-better-way-of-publishing-global-constants-in-java

标签

java

enums

singleton

global

final