That sounds like not very durable design if a single mis-config can break 'whole system'. Consider changing your OSGi code in a way that default value is always set. E.g. your Java code know's what the defaults are.
Thanks for your response, you are correct Peter but in OSGi we are using some key for lead submit. In case this property is blank then the whole system is breaking even though there is default value. So we need validation for not blank.