Is there an implementation of JSR-303 (bean validation) available?

Hibernate Validator is the reference implementation of JSR-303

Implementations:

• agimatec-validation
• Hibernate Validator

There are 2 compliant implementations now:

• Apache Bean Validation (formerly agimatec)
• Hibernate Validator

You can access a benchmark and a quick description of both here: http://carinae.net/2010/06/benchmarking-hibernate-validator-and-apache-beanvalidation-the-two-jsr-303-implementations/