This document discusses validation in Hibernate Validator, including: - Implementing simple and complex bean validation as well as custom constraints - Adding Hibernate Validator to projects - Using built-in constraints and declaring method constraints - Grouping constraints, combining constraint groups, and converting between groups - Creating custom constraints by defining an annotation and implementing a validator - Details on constraint violation structure and other features like fail fast mode and constraint composition

1. Iaroslav Gutsul

2. What is value from validation?
What is possible place for validation?
What is right place for validation?
What is correct implementation of
validation?

3. How to implement … with Hibernate
Validator
 simple bean validation
 simple method validation
 complex bean validation
 custom constrain for validation

4. What is with Hibernate Validator?
• validation framework based on metadata model (annotations)
• implements JSR 349 (Bean Validation 1.1) specification
• provides under Apache Software License 2.0

5. How to add Hibernate Validator to my
project?
Required
Optional

6. Basic bean validation
 Field-level constraints
 Property-level constraints
 Class-level constraints
 Constraint inheritance

7. Cascade validation with @Valid

8. Validator methods
Validator#validate()
Validator#validateProperty()
Validator#validateValue()

9. Built-in constraints
@AssertFalse
@Future
@Max(value=)
@Min(value=)
@DecimalMax(value=,
inclusive=)
@NotNull
@Valid
@Size(min=, max=)
@NotEmpty
@Pattern(regex=, flag=)

10. Declaring method constraints
 Parameter constraints
 Return value constraints
Cross-parameter constraints

11. Error Message
default message
custom message source

12. Grouping constraints
Validation group = java interface
Add group to validation property
Validation with group

13. Grouping constraints combination
@GroupSequence
@GroupSequenceProvider (PROVIDER)
PROVIDER implements DefaultGroupSequenceProvider<T>
provide list of validation groups based on object stage
@ConvertGroup(from = GROUP_A.class, to = GROUP_B.class)
during validation with group A will be used rules from both
groups

14. Creating custom constraints
Create a constraint annotation
Implement a validator
Define a default error message

15. Create a constraint annotation with
default error message

16. Implement a validator

17. ConstraintViolation Structure

18. Interesting Notes
 Fail fast mode
 Boolean composition of constraints in custom constrain
@ConstraintComposition(OR)
CompositionType with its values AND, OR and ALL_FALSE.
Validation of Null by default return true

19. Thank you!
Questions?