On 9/3/07, Brian McCallister <[EMAIL PROTECTED]> wrote: > > On Sep 3, 2007, at 7:07 AM, Hadrian Zbarcea wrote: > > > On the CAMEL-84 topic, I think returning null is a valid normal > > case, not an exceptional one. If a null is an acceptable answer is > > imho for the caller to decide (which is what the JournalEndpoint in > > jpa does already). > > Actually, the exception is what makes NULL a valid value. If NULL can > be both a valid value and no-conversion-available, you caannot know > which one it is. > > If the journal or jpa decide to return null for correct reasons (I am > curious when this would be correct, but that is a tangent) then they > may throw an exception in the case where they couldn't convert. Now > you get both worlds.
I guess thats the thing; if NULL is a valid type conversion result, then we need an exception to differentiate. I can't think of too many sane examples of NULL being a valid type conversion result though :). But I guess the lack of a type converter should be considered an exceptional case. Imagine a use case where a type converter lives in some jar on the classpath; things are working great, but then at a later date, someone removes something from the classpath; all of a sudden we're gonna have null payloads in messages and no real exception / log / knowledge of why things just started failing. So I'm kinda thinking we should patch the use of 'null' as no type conversion available and instead use exceptions. (Its gonna take a while to convert all the type conversion code to use this model though). -- James ------- http://macstrac.blogspot.com/
