Assume I want to add some logical constraints to certain fields.
For example the value of field20 must be between 210 and 220
or the maxlength of string variable stringABC must be lower than 20
how can I achieve this with Hibernate?

I heard that I can use the built-in validator.
But how does that work?

I am not searching for a comprehensive reference guide
but a simple example or step-by-step guide.
Something like a "Hello world" for applying the validator for say the both constraints mentioned above.

Peter

Hi,

I think you should look at Hibernate Validator. Constraints are defined by annotations like in the example on the online doc - http://www.hibernate.org/hib_docs/validator/reference/en/html_single/#d0e319. Get the latest release, add the jars to your classpath, annotate your domain model with constraints and call ClassValidator. As easy as that.

There is also soon a reference implementation of JSR 303 available which will replace Hibernate Validator. However, we are planning to offer some sort of transparent bridging for people using Hibernate Validator.

--Hardy