Understanding Bean Validation 2.0

Validating data is a common task that Java developers have to do and it is spread throughout all layers (from client to database) of an application. This common practice is time-consuming, error prone, and hard to maintain in the long run. Besides, some of these constraints are so frequently used that they could be considered standard (checking for a null value, size, range, etc.). It would be good to be able to centralise these constraints in one place and share them across layers.That's when Bean Validation comes into play.In this fascicle, you will learn Bean Validation and use its different APIs to apply constraints on a bean, validate all sorts of constraints, write your own constraints and a few advanced topics such as integrating Bean Validation with other frameworks (JPA, JAX-RS, CDI, Spring).