JSR-303 bean validation is an specification whose objective is to standardize the validation of Java beans through annotations. The objective of the JSR-303 standard is to use annotations directly in a Java bean class.

How can you explain Bean validation?

JavaBeans Validation (Bean Validation) is a new validation model available as part of Java EE 6 platform. The Bean Validation model is supported by constraints in the form of annotations placed on a field, method, or class of a JavaBeans component, such as a managed bean. Constraints can be built in or user defined.

What is Bean Validation API?

Bean Validation defines a metadata model and API for JavaBean validation. The metadata source is annotations, with the ability to override and extend the meta-data through the use of XML validation descriptors. Originally defined as part of Java EE, version 2 aims to work in Java SE apps as well.