Grouping Constraints

Java Platform, Enterprise Edition (Java EE) 8
The Java EE Tutorial

Grouping Constraints

Constraints may be added to one or more groups. Constraint groups are used to create subsets of constraints so that only certain constraints will be validated for a particular object. By default, all constraints are included in the Default constraint group.

Constraint groups are represented by interfaces.

public interface Employee {}

public interface Contractor {}

Constraint groups can inherit from other groups.

public interface Manager extends Employee {}

When a constraint is added to an element, the constraint declares the groups to which that constraint belongs by specifying the class name of the group interface name in the groups element of the constraint.

@NotNull(groups=Employee.class)
Phone workPhone;

Multiple groups can be declared by surrounding the groups with braces ({ and }) and separating the groups' class names with commas.

@NotNull(groups={ Employee.class, Contractor.class })
Phone workPhone;

If a group inherits from another group, validating that group results in validating all constraints declared as part of the supergroup. For example, validating the Manager group results in the workPhone field being validated, because Employee is a superinterface of Manager.

Customizing Group Validation Order

By default, constraint groups are validated in no particular order. There are cases in which some groups should be validated before others. For example, in a particular class, basic data should be validated before more advanced data.

To set the validation order for a group, add a javax.validation.GroupSequence annotation to the interface definition, listing the order in which the validation should occur.

@GroupSequence({Default.class, ExpensiveValidationGroup.class})
public interface FullValidationGroup {}

When validating FullValidationGroup, first the Default group is validated. If all the data passes validation, then the ExpensiveValidationGroup group is validated. If a constraint is part of both the Default and the ExpensiveValidationGroup groups, the constraint is validated as part of the Default group and will not be validated on the subsequent ExpensiveValidationGroup pass.

Contents