Bean Validation defines a metadata model and API for JavaBeanvalidation. 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 inJava SE apps as well. JavaBean Validation originated as a framework that was approved by the JCP as of 16November 2009 and accepted as part of the Java EE 6 specification. The Hibernateteam provides with Hibernate Validator the reference implementation of Bean Validation and also created the Bean Validation TCK any implementation of JSR 303 needs to pass.
Current Version
Bean Validation 2.0 is defined by , approved 2017-07-31. This major release leverages language features in Java 8 that are very useful for the purposes of Bean Validation. So Java 8 is required as the minimum Java version. Other changes include:
Support for validating container elements by annotating type arguments of parameterized types, e.g. List<@Positive Integer> positiveNumbers; this also includes:
*More flexible cascaded validation of collection types; e.g. values and keys of maps can be validated now: Map<@Valid CustomerType, @Valid Customer> customersByType
*Support for custom container types by plugging in additional value extractors
Support for the new date/time data types for @Past and @Future; fine-grained control over the current time and time zone used for validation
New built-in constraints: @Email, @NotEmpty, @NotBlank, @Positive, @PositiveOrZero, @Negative, @NegativeOrZero, @PastOrPresent and @FutureOrPresent
All built-in constraints are marked as repeatable now
Parameter names are retrieved using reflection
ConstraintValidator#initialize is a default method
The namespace for Bean Validation XML descriptors has been changed to http://xmlns.jcp.org/xml/ns/validation/configuration for META- INF/validation.xml and http://xmlns.jcp.org/xml/ns/validation/mapping for constraint mapping files
Previous Version
Bean Validation 1.1 improves upon the initial version 1.0. Significant changes include:
