validate properties (from .cfg) in blueprint routes

[Jv Naidu]

I have defined property placeholder in blueprint.xml of osgi bundle.

<cm:property-placeholder id="properties" persistent-id="myappconfig" />

and i have myappconfig.cfg  placed in etc folder of servicemix. This is
working as expected as i have been using like <from
uri="timer://apptimer?fixedRate=true&amp;period={{property1}}" />


Now i would like to validate properties  if property1 doesnt exist then use
property2 ?   and also i have to log the message if property does not exist
 ?

I would like to add validtion why because Bundle is failed and  not
executing other routes in blueprint dure to  error in single route.

 Any help much appreciated.

-- 
Thanks
Naidu