Hi
i was trying to play around latest jigsaw version in order to adapt an open
source projet that i developed and i found the following issue.
When using a jar containing a class with no package, the modulefinder is
failing to create its module descriptor.
It guesses that it is an automatic module (unamed), but fails with the
following stack trace :
Exception in thread "main" java.lang.module.FindException: Unable to derive
module descriptor for:
D:\.m2\com\github\maven-nar\nar-maven-plugin\3.0.0\nar-maven-plugin-3.0.0.jar
at java.lang.module.ModulePath.readJar(java.base@9-ea/ModulePath.java:538)
at
java.lang.module.ModulePath.readModule(java.base@9-ea/ModulePath.java:273)
at java.lang.module.ModulePath.scan(java.base@9-ea/ModulePath.java:192)
at
java.lang.module.ModulePath.scanNextEntry(java.base@9-ea/ModulePath.java:144)
at java.lang.module.ModulePath.findAll(java.base@9-ea/ModulePath.java:120)
at test.Test.main(Test.java:46)
Caused by: java.lang.IllegalArgumentException: Empty package name
at
jdk.internal.module.Checks.requireJavaIdentifier(java.base@9-ea/Checks.java:70)
at
jdk.internal.module.Checks.requirePackageName(java.base@9-ea/Checks.java:93)
at
java.lang.module.ModuleDescriptor$Exports.<init>(java.base@9-ea/ModuleDescriptor.java:269)
at
java.lang.module.ModuleDescriptor$Exports.<init>(java.base@9-ea/ModuleDescriptor.java:266)
at
java.lang.module.ModuleDescriptor$Exports.<init>(java.base@9-ea/ModuleDescriptor.java:239)
at
java.lang.module.ModuleDescriptor$Builder.exports(java.base@9-ea/ModuleDescriptor.java:1347)
at
java.util.stream.ForEachOps$ForEachOp$OfRef.accept(java.base@9-ea/ForEachOps.java:184)
at
java.util.stream.DistinctOps$1$2.accept(java.base@9-ea/DistinctOps.java:175)
at
java.util.stream.ReferencePipeline$3$1.accept(java.base@9-ea/ReferencePipeline.java:195)
at
java.util.HashMap$KeySpliterator.forEachRemaining(java.base@9-ea/HashMap.java:1600)
at
java.util.stream.AbstractPipeline.copyInto(java.base@9-ea/AbstractPipeline.java:484)
at
java.util.stream.AbstractPipeline.wrapAndCopyInto(java.base@9-ea/AbstractPipeline.java:474)
at
java.util.stream.ForEachOps$ForEachOp.evaluateSequential(java.base@9-ea/ForEachOps.java:151)
at
java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(java.base@9-ea/ForEachOps.java:174)
at
java.util.stream.AbstractPipeline.evaluate(java.base@9-ea/AbstractPipeline.java:234)
at
java.util.stream.ReferencePipeline.forEach(java.base@9-ea/ReferencePipeline.java:430)
at
java.lang.module.ModulePath.deriveModuleDescriptor(java.base@9-ea/ModulePath.java:435)
at java.lang.module.ModulePath.readJar(java.base@9-ea/ModulePath.java:534)
... 5 more
when looking in the class ModulePath, in the method deriveModuleDescriptor, the
problem seems to come from the following code
// all packages are exported
classFiles.stream()
.map(c -> toPackageName(c))
.distinct()
.forEach(builder::exports);
when the class has no package, toPackageName returns "", and builder::exports
throws an exception.
Easy fix could be to assert in the forEach before calling builder::exports
Thank you
