Name: ssT124754 Date: 02/16/2001


java version "1.2.3"

There is a flaw in the implementations of ResourceBundle and
PropertyResourceBundle which makes it difficult to extend ResourceBundle while
leveraging its bundle-finding code.

I needed to extend ResourceBundle to make a class which
locates and loads XML files (in much the same way that a
PropertyResourceBundle finds and loads .properties files).

I assumed that studying the implementation of PropertyResourceBundle
would yield the "right" way to implement this, one which leverages
as much of the existing framework as possible.

I was disappointed to discover that the functionality which SHOULD be
implemented in PropertyResourceBundle is actually hard-coded into the base
class, ResourceBundle. Consider the implementation
of ResourceBundle.findBundle():

            // Next search for a Properties file.
            searchName = baseFileName + localeStr + ".properties";
final String resName = searchName;

The implementation makes it difficult to extend ResourceBundle without
duplicating a fair amount of the base class's code. Sun has the luxury of
tweaking the base class to get desired functionality in subclasses, but a Java
developer does not.
 
I imagine this was done because the ResourceBundle class does not expose the
granular functionality that would allow subclasses to leverage and extend the
bundle-finding logic. The findBundle() method is rather long and I think it
could be broken up and exposed without violating any representation invariants.
(Review ID: 117103)
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