Hibernate Validator allows to express and validate application constraints.
When defining the resource type, focus on what the resource can do, not how it does it.
It is not tied to a specific application tier or programming model and is available for both server and client application programming.
But a simple example says more than 1000 words: Hibernate Validator offers additional value on top of the features required by Bean Validation.
Method Options option (my_file_option) = "Hello world!
you could declare extensions of Field Options and Message Options with the same number.