> > My questions are then:
> > - is there any differences between the code sources of the different
> > binaries JDK 1.3, JDK 1.4, JDK 1.5, JDK 1.6?
> > - if yes, what are they? and what should we be aware when choosing?
> > - if no, I suppose then the only difference is to compile with target
> > 1.x, then why doing so?
>
> Mark answered your question already. The reason is to compile the jars
> on different platforms. I am not sure if I get Jaybird for Java 6
> running on Java 5, but I can check.

Jaybird itself might work since it does not follow JDBC 4.0 in all its details yet, but in general using a JDBC 4.0 compliant implementation can/will(?) fail on Java 5 due to missing interfaces and classes defined in java.sql and javax.sql (especially the changes in the exception hierarchy, since there weren't any new interfaces AFAIK). Some drivers do work around that though by using factories.
--
GMX FreeDSL Komplettanschluss mit DSL 6.000 Flatrate und Telefonanschluss
für nur 17,95 Euro/mtl.!* http://portal.gmx.net/de/go/dsl02