I have the following question about JPA:
Can I save the order of the elements in a java.util.List? In my application the order in which I put elements in the Lists is im
JPA has 2 types of Lists. In JPA1 there is an "ordered list" (which is what you see, ordering defined by some SQL clause). In JPA2 you can have "ordered lists" or alternatively "indexed lists" (where the order of creation is preserved) ... the @OrderColumn referred to. Any implementation of JPA2 will have to support this e.g DataNucleus.
JDO has had indexed lists since day 1