Question

Is there any naming convention for java constant variable?
Normally we use variables with names containing uppercase letters and underscores(_).

For example:

public final class DeclareConstant {

    public static final String CONSTANT_STRING = "some constant";

    public static final int CONSTANT_INTEGER = 5;

}

Answer 1

Yes. That is it. It is often used for enum as well.

The only common exception is for logging where you might see

private static final Logger log = Logger.getLogger(getClass().getName());

but I prefer LOG

I often write this as UPPER_CASE, but I also write TitleCase for classes and camelCase for variables and methods.