I am in the process of upgrading my application to Hibernate3 and things are going well with one exception. One of my sets is sorting in the wrong order.

Here is the relevant .hbm snippet:


As you can see, there is a comparator to do the sorting. However, I notice that this comparator is not being called. For example, I have some test code:

The output shows that the start dates are sorted from last to first, not first to last. My initial thought was that somehow my comparator worked fine on Hibernate 2.1, but somehow there was a subtle bug that caused my comparator to fail in Hibernate 3. But instrumenting the comparator seems to indicate that it is not even being called.

I have tried modifying the Set above to be a SortedSet, but no change (and that required me to modify the code that HibernateSynchonizer generated).

I have also looked at the generated SQL and I do not see any order by clauses being generated.

Any ideas as to what I may have stumbled into are greatly appreciated!

Thanks SO much!
RB

Another clue that the problem is that the Comparator is not being called (vs. the comparator being wrong). I inverted the logic in the Comparator, which should have reversed the sorting - but there was no difference. Of course, the fact that the println statements that I have in the Comparator don't print out anything is the real evidence that the Comparator is not being called).

Now why would the Comparator not be called if the .hbm file clearly specifies a sort. (I am sure that there is a logical explanation for all this).

TIA,
RB

In further reading and experimenting, I was able to work around my problem - but on the surface, there does appear to be some change in Hibernate3.

In particular, I was able to get sorting to work by implementing the compareTo method in my ChildInCampWeek class (the class that also has the ChildInCampWeekComparator inner class).

I ran my test and saw that the compareTo method was the method that was being called to do the sorting. It appeared that the:

was being ignored. And, now that I had a compareTo method, sorting worked fine.

I went and changed my Child.hbm to use:

and everything continued to work fine.

Upon reflection, it turns out that the right (and easier) way for me to do things is to have the compareTo and use sort="natural", but the mystery remains as to why sorting using the Comparator stopped working when I upgraded to Hibernate3 (and the associated HibernateSynchronizer plugin).

Anyone have any ideas? (I hate having unresolved myteries :) ).

Thanks!!
RB