[hibernate-issues] [Hibernate-JIRA] Resolved: (HV-404) Simplify creation of ConstraintDef derivations

Simplify creation of ConstraintDef derivations ---------------------------------------------- Key: HV-404 URL: http://opensource.atlassian.com/projects/hibernate/browse/HV-404 Project: Hibernate Validator Issue Type: Improvement Components: engine Affects Versions: 4.1.0.Final Reporter: Gunnar Morling Assignee: Hardy Ferentschik When working with the programmatic constraint declaration API one typically creates a constraint definition type (derivation of ConstraintDef) for each constraint type. In its current form the API requires that in each such ConstraintDef sub-type the methods message(), payload() and groups() are overridden to have the fluent invocation style working properly. If for instance message() were not overridden in SizeDef, invoking this method would return the type ConstraintDef, hindering to call later on a specific SizeDef member such as min(). This can be improved by making ConstraintDef a so called self referential type as follows: {code:java} public abstract class ConstraintDef<C extends ConstraintDef<C, A>, A extends Annotation> { //... public C message(String message) { //... } } {code} That way overriding said methods in concrete definition types is not necessary any more while still allowing the fluent invocation style, as message() would return SizeDef when called on a SizeDef instance.