RFR 7199353: Allow ConstructorProperties annotation from any package
Alan.Bateman at oracle.com
Fri Oct 9 16:54:58 UTC 2015
On 09/10/2015 16:36, Peter Levart wrote:
> Sorry, but I must be missing something.
> When you compile a class (not an MXBean as Daniel pointed out, but a
> data object class) with JDK9, it can't be used on JDK8 because of
> class file version.
> When you compile a class with JDK8, it can't contain new @CS
> annotation, because it is not part of the official Java SE API on the
> Java 8 platform.
> So I still don't see how one could compile a data class so that it
> could be used on JDK8 as well as on JDK9 without java.desktop module?
I think you have it right as there isn't a @CP that works for this
scenario. The compiling with JDK 8 and trying to deploy on runtime that
only has a subset of the standard modules is essentially the scenario
that is already warned about in the javadoc:
"Rule 2 is not applicable to subset Profiles of Java SE that do not
include the java.beans package. When targeting a runtime that does not
include the java.beans package, and where there is a mismatch between
the compile-time and runtime environment whereby J is compiled with a
public constructor and the ConstructorProperties annotation, then J is
not reconstructible unless another rule applies."
A solution that updates Java SE 8 to specify the new @CP or having it
using method parameters would require doing a MR of Java SE 8 and I
doubt it's important enough to go justify that.
Possible workarounds are to compile on JDK 8 with "-profile compact3" as
this should fail if there is code using @beans.CP. Another one would to
just define a static "from" method.
More information about the jigsaw-dev