building with JDK 7

[Rick Hillegas]

It seems that at least one other person has managed to trick the Derby 
build into working under JDK 7: 
https://issues.apache.org/jira/browse/DERBY-5310. I find that I can 
build Derby under the openjdk 7 preview for mac os x as long as I force 
the j16lib property to point into the jre library of my Java 7 
installation. That is, I have to trick the build into thinking that JDK 
7 is really JDK 6.

It doesn't appear to me that any support for JDK 7 has been added to 
PropertySetter. That's the ant task which sets up the Derby build 
environment. Is this a fair summary of how we expect the Derby build to 
work under JDK 7:

1) Out-of-the-box the build will fail because the build does not 
consider Java 7 installations.

2) In order to build under JDK7 you have to trick the build into 
thinking that your Java 7 installation is really Java 6 (e.g., by 
forcing the value of j16lib).

Thanks,
-Rick