I have three tables:

A: id (PK),name
B: id , sno, des (id and sno are composite key; id is the foreign key references A(id))
C: id , sno ,code ,des (id, sno,code are composite key; id and sno are the foreign key references B(id,sno))

How should i set the annotation java class about the three table.Now i use the A entity,B embeddable and CollectionOfElements,
and C is the same with B. But when save it, throw Caused by: java.util.ConcurrentModificationException.

Thanks!

I had problems with getting ConcurrentModificationException when I was displaying debug-logging from Hibernate. (I use log4j) When I rasied the log level of "org.hibernate" the problems went away.

Don't know if this is the problem you're having though..