The jdbc4.0 code base is not compiling against jdk6. The compilation fails with message that sun.reflect.misc package is missing. This package is present in rt.jar but missing from ct.sym. If ct.sym is removed, then compilation goes through.
There is a secret option, but it's super secret so if I told you, I might have to
enact nastiness to your person. However, if you were to read the compiler code on
OpenJDK and grep for ct.sym, you might quickly come to this line of code
ignoreSymbolFile = options.get("ignore.symbol.file") != null;
which might lead you to presume that -XDignore.symbol.file might have a not