Strategy to keep string constants in sync between java/flex?

Question

Say you have a web application that has a lot of business rules built around if-then comparison of String constants. These are used on both client-side and backend code, and at the moment are hard-coded badly throughout both places with lots of duplication and sometimes errors. What's a sensible way to refactor them out? Unfortunately, in most cases they must exist as using polymorphism would be much more hideous. Anything specific for flex/java? Is there an easy way to keep all those constants in one place and compile it into both client and server code?

Edit: I'm really looking for a way to share string constants between flex and java with compile-time checking of everything. The only idea I can think of is a code generator.

Answer 1

Keep them into a project that is being distributed as a jar. You can also place there all the util classes to avoid code duplication.

Answer 2

Don't both Flex and Java both have support for simple .properties files where the contents of those files are of this form

key1=value 1
key2=value 2

and so on...

So why not define a common .properties file and share it between your two projects? Your version control system could help here as well. For instance, if you were using svn you could just put your .properties files in another repository and use svn:externals to share them between both your flex and java repository.

As for loading and using the properties, the following pages show how to do it in each language/platform:

For Java: http://www.mkyong.com/java/java-properties-file-examples/

For Flex: http://vatsalad.wordpress.com/2010/03/12/how-to-use-properties-fileresourcebundle-in-flex/

Answer 3

Code generation is easier than you think. If you really believe that's what you need to do, I could possibly provide an example (a custom Ant task although it can be run as a plain java 'main' app) that you could modify for your purposes (specifically for string constants) if you want.

If I understand correctly, you're looking for something which provides you with compile-time "key" checking (which would also give you auto-complete support)? So yes, a properties file wouldn't help much here.