Interface and Class

Question

Hi pls any one can help me ?. In most of all the places we are declaring the constance in class files as
class A{
public static final String str_Constant;
After that we will refer this like "A.str_Constant"
Why we cant define it in interface like
interface A{
String str_Constant;
and refer like A.str_Constant
Thanks in advance

Answer 1

Not static either:The "static final" modifier is implied, since it doesn't make sense to have non-static, non-final variables in an interface. The way to go is to do this:
public interface Constants {
   public static final int SOME_CONSTANT = 0;
}This works if you have package-spanning consants (such as SwingConstants), but if you have class-specific constants you should gather them inside the class:
public class Stylesheet {
   public static final int BACKGROUND = 0;
   public void set(int arg, Object value) { ... }  
myStylesheet.set(Stylesheet.BACKGROUND, Color.white);But this doesn't look very good (see enum's in 1.5), so it's probably better do solve it in some other way (depends on the project).
Regards,
Nille