Hi
[The question needs to be more clear, but somehow am able to get what you are looking for.]
My assumption:
When you get an error, you would pass your error object to an logging class, which will decide at runtime-
if it is an error (?) or just an info (?) and log that into appropriate source (like file, DB etc)
If yes, I would recommend to go for a Chain Of Responsibility pattern.
Steps I could think of :"
1) Build the chain of Loggers (File, email, DB etc.,)
2) Pass the error (or Info) obejct to First in the chain , say File Logger, this Class will decide if it need to log, if yes, will log and then send your "Error object" to next in the chain - say "Email Logger (sender)"
3) Email Logger Class will check if it eligible to be sent , if yes will send email and will pass it to next in the chain, say DB.
4) DB Logger will check and lets us assume its not a eligible one and will end the chain signallig the completion.
Please refer to my blog where I have talked more about this pattern (of course with a Builder Pattern variation)
http://techietarriq.blogspot.com/2011_02_01_archive.html
Hope this helps.
Thanks,
Tarriq Ferrose Khan