JPackage with a modular application fails to load record class files even with --enable-preview

[Andy Herrick]

So when you use the jpackage option "--java-options --enable-preview" it 
appears to work with a non-modular jar, but not with a modular jar ?

I think I can create a testcase for that.

Have you tried it with the jpackage from a preview release of JDK15  
(https://jdk.java.net/15/) ?

Can you look at the runtime in the app-image of the failing case, and 
see if the preview module is there ?  Perhaps the problem is the way 
jpackage invokes jlink.

A final thing you can try is run jlink yourself, and use the resulting 
runtime-image in jpackage args.

/Andy

On 6/7/2020 9:07 AM, Markus Jevring wrote:
> I have this app, which uses Java 14 with –enable-preview and records. If I turn it in to a normal non-modular jar, it works with both java -jar –enable-preview myapp.jar, and with a native image built with jpackage. However, when i turn it into a modular jar, I can still launch it with java –enable-preview –module-path ... –module ..., but  when I try to create a native image using jpackage usign the same modular flags, launching it fails. I get a dialog box saying “Failed to launch JVM”, and if I enable –win-console when I build it and relaunch it, it tells me this:
>
> Exception in thread "main" java.lang.ClassFormatError: Invalid constant pool index 31 for name in Record attribute in class file net/jevring/frequencies/v2/input/KeyTimings$Note
>          at java.base/java.lang.ClassLoader.defineClass2(Native Method)
>          at java.base/java.lang.ClassLoader.defineClass(Unknown Source)
>          at java.base/java.security.SecureClassLoader.defineClass(Unknown Source)
>          at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(Unknown Source)
>          at java.base/jdk.internal.loader.BuiltinClassLoader.findClassInModuleOrNull(Unknown Source)
>          at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(Unknown Source)
>          at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source)
>          at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(Unknown Source)
>          at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
>          at frequencies/net.jevring.frequencies.v2.input.KeyTimings.<init>(Unknown Source)
>          at frequencies/net.jevring.frequencies.v2.Thief.<init>(Unknown Source)
>          at frequencies/net.jevring.frequencies.v2.Main.main(Unknown Source)
>
> Note, above, is a record. I tried moving it out to a separate class, and I still got the same error. When I converted Note to a normal class, it started complaining about the next record it cound.
> I know that it’s picking up the –enable-preview java option, because when I omit that, it complains about the class file version being wrong.
>
> Since I can run it just fine using “java -jar”, and it works fine under all other circumstances, I must conclude that there’s something wrong with the intersection of modular jars and jpackage.
> I’ve googled around plenty, and I haven’t found anything that might help me. I’m not sure if this is a call for help or a bug report, though I’d like to consider it the latter =)
>
> I put what I had on a branch: https://bitbucket.org/jevring/frequencies/branch/java-modules
> I realize it’s not a small self-contained example that replicates the issue, and for that I’m sorry. If someone is interested about this, I could try to make one.