Hi We are planning to use Apache commons validator for input data validation at the Web Service Provider layer. has anyone used this validator framework at Web Service provider layer? If not, what are the other alternatives available? When I say Input data Validation I want to achieve following things : 1. Data Field Syntax validation.. ( I can use XML Schema) 2. Symatic validation ( Inter field validations) 3. Some business rules - like Credit card formats etc Please suggest