I'm saving result from a calculation. Sometime the result can be the Double NaN (perfectly legal in our domain problem), but then, when Hibernate try to write it to the database, the call.

generate an IllegalArgumentException. Do you think that DoubleType should check for this or is the domain code that must take care of NaN ?
Ciao.

hmm....what is the exact exception ?

And can jdbc databases store NaN per default ? (I don't know actually ;)

Almost no jdbc drivers handle NaN properly. Check against NaN and convert to null as required (Hibernate should do this)

You are COMPLETELY rigth, the problem is inside the Oracle Jdbc driver.
But the fact is that Hibernate write on relational DB, so, I think, should check for data not compatible with relational model.
The exact exception is inside the Oracle JDBC driver, do you want the Exception log ?
Ciao.

don't need the exception.

The problem with making hibernate handle NaN => null is that

would make Double and double behave differently!

With Double null in db would be null in java
with double null in db would be NaN ....which is not nice.

Sorry, but I can't follow you Max. NaN is a double, not a Double, is exactly the double representing 0x7ff8000000000000L.
So DoubleType can have the same, identical, problem, with primitive double containing NaN.
Sure putting NaN ==> null is not a solution.
Ciao.

Yes - but a Double also can be set to a NaN....

..but if you can tell me how to store 0x7ff8000000000000L (or more precise Double.NaN) into a db - then we can make hibernate do it.....

Thinking about the problem........it's not as easy-solvable as I thougth initially.
The question is "Should Hibernate allow something like a Dialect to manage this kind of numbers?"
Infact, as Max let me notice, AFAIK there is not a Relational approach to this problem, so every mapping should be Database dependent, or signal an error from Hibernate (or also from JDBC driver, if you prefere).
What do you think ?

I would suggest a UserType for such feature.