Here goes: Currently have a j2ee web app - client side input is validated before an entity bean can be poulated to ensure it is of the correct type, correct length etc. While this is all well and good - I still feel that the biz objects themselves should either be able to validate themselves (the data for this field is too long, I cannot update rather than have it throw a sql exception which causes other issues), or have some logic on the session beans that are doing the updating. I could always put something in the session bean which would validate every field, but this seems, well, bad. Is there any way to pull this info from the data source? ie: database column size, type, etc... Are there any lightweight validation frameworks out there for the business side - like I said, the client tier/view is covered. Thanks.