[ http://opensource.atlassian.com/projects/hibernate/browse/ANN-9?page=com.... ] Paul Singleton Kossler commented on ANN-9: ------------------------------------------ I am curious as the state of this improvement. It is mentioned in the "Java Persistence with Hibernate "from Manning press. Though the last traffic on this was a year ago. This feature helps the community by reducing the complexity of the build environment as well as reducing the number of files to track per class. @Entity can handle mapping an Interface as follows: //----------------- @Entity public interface A { @Transient public B getB(); public void setB(B b); @Transient public C getC(); public void setC(C c); } public class B{} public class C{} //------------------------ In this case a a simple POJO getter/setter can be mapped with @Transient to denote that the actual persistence mapping annotations are only on the abstract or concrete class that actually contains information to be persisted. Since a Java interface is the same as a pure virtual class in C one could take this one step further and allow @Transient assignment at the Class level. This would denote that this class is not a class it is an interface (Can be checked with a guard on compile) This would allow the SessionManager to determine the type of Entity: Real or Reference for class and interfaces respectively. I may be going down a side path in this thought process; however, the @org.hibernate.annotations.Entity could also have an addition attribute "interface" such that: @org.hibernate.annotations.Entity(interface="true") defaulting to false; will keep this inline with the JPA spec and as an extension of a class level annotation this makes the @Transient annotations redundant so the Interface could be mapped more simply too: //----------------- @Entity(interface="true") public interface A { public B getB(); public void setB(B b); public C getC(); public void setC(C c); } public class B{} public class C{} //------------------------ I hope this helps out other developers. If I am inaccurate on the forum/implementation level I do apologize. Unfortunately looking up the word "interface" with Hibernate and Java is ambiguous, making it difficult to narrow in on. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira