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Groups > comp.lang.java.programmer > #8272

Re: borrowing Constants

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On Fri, 23 Sep 2011 17:40:20 -0700, Roedy Green
<see_website@mindprod.com.invalid> wrote, quoted or indirectly quoted
someone who said :

>class A
>{
> static String VERSION = "1.0b";
>}
>
>and 
>class B
>{
>static String VERSION = A.VERSION;
>}

restating, if the expression for A.VERSION cannot be evaluated an
compile time, even final won't rescue you from having to include both
A in your jar and indirectly loading A when you load B.

So the rule of thumb use static final with values known at compile
time to avoid needless class loading. But be aware, you must recompile
B if the value of A.VERSION changes, or you will get the old value.

Another rule of thumb may be, instead of cross linking classes with
references to each others constants, refactor out the constants to a
third class, and reference it or extend it.

In a number of my projects I have a Config class where everything
constant (possibly computed)  needed to configure a program for a
particular use are collected.
-- 
Roedy Green Canadian Mind Products
http://mindprod.com
It should not be considered an error when the user starts something
already started or stops something already stopped. This applies
to browsers, services, editors... It is inexcusable to 
punish the user by requiring some elaborate sequence to atone,
e.g. open the task editor, find and kill some processes.

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borrowing Constants Roedy Green <see_website@mindprod.com.invalid> - 2011-09-23 17:40 -0700
  Re: borrowing Constants Arne Vajhøj <arne@vajhoej.dk> - 2011-09-23 20:44 -0400
    Re: borrowing Constants Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-09-23 22:10 -0300
      Re: borrowing Constants Roedy Green <see_website@mindprod.com.invalid> - 2011-09-23 18:39 -0700
        Re: borrowing Constants Arne Vajhøj <arne@vajhoej.dk> - 2011-09-23 22:17 -0400
        Re: borrowing Constants Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-09-25 11:25 -0700
          Re: borrowing Constants Lew <lewbloch@gmail.com> - 2011-09-25 11:36 -0700
      Re: borrowing Constants Arne Vajhøj <arne@vajhoej.dk> - 2011-09-23 22:30 -0400
  Re: borrowing Constants Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-23 21:15 -0400
    Re: borrowing Constants Roedy Green <see_website@mindprod.com.invalid> - 2011-09-23 18:43 -0700
  Re: borrowing Constants markspace <-@.> - 2011-09-23 18:44 -0700
    Re: borrowing Constants Lew <lewbloch@gmail.com> - 2011-09-23 19:19 -0700
    Re: borrowing Constants Arne Vajhøj <arne@vajhoej.dk> - 2011-09-23 22:32 -0400
  Re: borrowing Constants Lew <lewbloch@gmail.com> - 2011-09-23 19:11 -0700
    Re: borrowing Constants Lew <lewbloch@gmail.com> - 2011-09-23 19:26 -0700
  Re: borrowing Constants v_borchert@despammed.com (Volker Borchert) - 2011-09-24 09:44 +0000
  Re: borrowing Constants Roedy Green <see_website@mindprod.com.invalid> - 2011-09-24 15:38 -0700
  Re: borrowing Constants Roedy Green <see_website@mindprod.com.invalid> - 2011-09-24 17:09 -0700
    Re: borrowing Constants Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-24 20:14 -0400
    Re: borrowing Constants markspace <-@.> - 2011-09-24 18:18 -0700
      Re: borrowing Constants Arne Vajhøj <arne@vajhoej.dk> - 2011-09-25 22:36 -0400
    Re: borrowing Constants Arne Vajhøj <arne@vajhoej.dk> - 2011-09-25 22:35 -0400
  Re: borrowing Constants Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-09-26 01:22 +0200

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