[cdi-dev] [JBoss JIRA] (CDI-403) why decorator requires interface

why decorator requires interface -------------------------------- Key: CDI-403 URL: https://issues.jboss.org/browse/CDI-403 Project: CDI Specification Issues Issue Type: Feature Request Reporter: Mathieu Lachance Labels: F2F2016 Fix For: 2.0 (discussion) As discussed with Jozef Hartinger on the WELD forum thread (see forum reference and CDI-224), would it be possible to revisit why decorator requires an interface ? I do not understand the semantic difference between: 1. a decorator to be an abstract class which implements an interface, which delegate to the same interface. 2. a decorator to be a concrete class which extends a another class, which delegates to the same class. Why 1. should be allowed and why 2. should be disallowed ? As stated in CDI-224, if there is no technical reason of disallowing 2., should it be then considerate as a vendor specific feature to support it whether or not ? It is kind of sad that only decorators requires an interface while all the others Java EE 6 features do not. Thanks,