RFR 7199353: Allow ConstructorProperties annotation from any package

[Alan Bateman]

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.

-Alan.