Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #8761

Re: Substitute value in HashMap at runtime

Show all headers | View raw

On Oct 13, 2:18 pm, mike <mikaelpetter...@hotmail.com> wrote:
> If I create a HashMap with something like:
>
> static Map<String,String> map = new
> HashMap<String,String>("variable",MyPreferences.getVariableValue());
>
> If I do it like this I guess that MyPreferences.getVariableValue()
> will not be substituted but be the "plain" string.
>
> How can I make my MyPreferences.getVariableValue() be evaluated at
> runtime? Any example?

One possible way is to change your Map to Map<String,
Callable<String>> and invoke call() at runtime.

http://download.oracle.com/javase/6/docs/api/java/util/concurrent/Callable.html

Of course you then need to provide a proper implementation. :-)

Btw, does your Map contain more entries?  If not, it's completely
superfluous.

If you define the Map as static you also need to be aware of
concurrency issues if your application will ever access this from
multiple threads.

Cheers

robert

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Substitute value in HashMap at runtime mike <mikaelpetterson@hotmail.com> - 2011-10-13 05:18 -0700
  Re: Substitute value in HashMap at runtime Lew <lewbloch@gmail.com> - 2011-10-13 05:53 -0700
  Re: Substitute value in HashMap at runtime Robert Klemme <shortcutter@googlemail.com> - 2011-10-13 06:44 -0700
    Re: Substitute value in HashMap at runtime Lew <lewbloch@gmail.com> - 2011-10-13 10:12 -0700
      Re: Substitute value in HashMap at runtime mike <mikaelpetterson@hotmail.com> - 2011-10-14 06:36 -0700
        Re: Substitute value in HashMap at runtime mike <mikaelpetterson@hotmail.com> - 2011-10-14 06:54 -0700
          Re: Substitute value in HashMap at runtime markspace <-@.> - 2011-10-14 08:13 -0700
  Re: Substitute value in HashMap at runtime Roedy Green <see_website@mindprod.com.invalid> - 2011-10-14 09:40 -0700

csiph-web