Request for comments: Bug 6306820

[Alan Bateman]

Richard Kennard wrote:
> Alan,
>
> Thanks for your continued support.
>
> I find the 'static factory method' approach interesting, but I'm a 
> little confused. You cite 'being able to return a subclass' as an 
> advantage. However, you also recommend a private constructor and 
> classes with private constructors can never be subclassed?
Josh Bloch's Effective Java provides good coverage of this topic if you 
are interested. In this case the static factory methods that you define 
will create the UrlQueryString instances and they can return different 
subtypes if required. This might not be necessary now but in the future 
there may be differnt standards for encoding parameters and to support 
that you could add a new static factory method that returns a 
UrlQueryString that supports that mechanism. If it becomes necessary to 
return subtypes from other classes in the package then you could make 
the constructors package-private but for the current proposal it 
probably isn't necessary.

-Alan.