Design patterns for validating a file

Question

We have to validate a CSV file containing various configuration parameters. Are there any standard design patterns to do this type of validation.

More details:

• There are different types of records - each with their own validation logic
• Certain records cross reference other records
• There are rules on the order of the records
• There are rules on the eligibility of duplicate records
• etc

Answer 1

The template pattern may help: http://en.wikipedia.org/wiki/Template_method_pattern

You set up a scaffolding for your validation in general terms, then hand off the algorithm to a delegate that knows how to handle specifics at various points.

Answer 2

I know a friend of mine uses JBOSS DROOLS to validate this kind of files.