I've put together a proof of concept which aims to provide a skeleton SBT multimodule project which utilizes DataNucleus JDO Enhancer with mixed Java and Scala sources.
The difficulty appears when I try to enhance persistence classes from SBT. Apparently, I'm not passing the correct classpath when calling Fork.java.fork(...) from SBT.
See also this question:
How can SBT generate metamodel classes from model classes using DataNucleus?
Exception in thread "main" java.lang.NoClassDefFoundError: Could not initialize class org.datanucleus.util.Localiser
at org.datanucleus.metadata.MetaDataManagerImpl.loadPersistenceUnit(MetaDataManagerImpl.java:1104)
at org.datanucleus.enhancer.DataNucleusEnhancer.getFileMetadataForInput(DataNucleusEnhancer.java:768)
at org.datanucleus.enhancer.DataNucleusEnhancer.enhance(DataNucleusEnhancer.java:488)
at org.datanucleus.api.jdo.JDOEnhancer.enhance(JDOEnhancer.java:125)
at javax.jdo.Enhancer.run(Enhancer.java:196)
at javax.jdo.Enhancer.main(Enhancer.java:130)
[info] Compiling 2 Java sources to /home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/klasses...
java.lang.IllegalStateException: errno = 1
at $54321831a5683ffa07b5$.runner(build.sbt:230)
at $54321831a5683ffa07b5$$anonfun$model$7.apply(build.sbt:259)
at $54321831a5683ffa07b5$$anonfun$model$7.apply(build.sbt:258)
at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)
at sbt.std.Transform$$anon$4.work(System.scala:63)
at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:226)
at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
at sbt.Execute.work(Execute.scala:235)
at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:226)
at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)
at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)
For the sake of completeness and information, below you can see a java command line generated by SBT which can be executed by hand on a separate window, for example. It just works fine.
$ java -cp /home/rgomes/.ivy2/cache/org.scala-lang/scala-library/jars/scala-library-2.11.6.jar:/home/rgomes/.ivy2/cache/com.google.code.gson/gson/jars/gson-2.3.1.jar:/home/rgomes/.ivy2/cache/javax.jdo/jdo-api/jars/jdo-api-3.0.jar:/home/rgomes/.ivy2/cache/javax.transaction/transaction-api/jars/transaction-api-1.1.jar:/home/rgomes/.ivy2/cache/org.datanucleus/datanucleus-core/jars/datanucleus-core-4.0.4.jar:/home/rgomes/.ivy2/cache/org.datanucleus/datanucleus-api-jdo/jars/datanucleus-api-jdo-4.0.4.jar:/home/rgomes/.ivy2/cache/org.datanucleus/datanucleus-jdo-query/jars/datanucleus-jdo-query-4.0.4.jar:/home/rgomes/.ivy2/cache/org.datanucleus/datanucleus-rdbms/jars/datanucleus-rdbms-4.0.4.jar:/home/rgomes/.ivy2/cache/com.h2database/h2/jars/h2-1.4.185.jar:/home/rgomes/.ivy2/cache/org.postgresql/postgresql/jars/postgresql-9.4-1200-jdbc41.jar:/home/rgomes/.ivy2/cache/com.github.dblock.waffle/waffle-jna/jars/waffle-jna-1.7.jar:/home/rgomes/.ivy2/cache/net.java.dev.jna/jna/jars/jna-4.1.0.jar:/home/rgomes/.ivy2/cache/net.java.dev.jna/jna-platform/jars/jna-platform-4.1.0.jar:/home/rgomes/.ivy2/cache/org.slf4j/slf4j-simple/jars/slf4j-simple-1.7.7.jar:/home/rgomes/.ivy2/cache/org.slf4j/slf4j-api/jars/slf4j-api-1.7.7.jar:/home/rgomes/workspace/poc-scala-datanucleus/model/src/main/resources:/home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/klasses javax.jdo.Enhancer -v -pu persistence-h2 -d /home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/classes
May 13, 2015 3:30:07 PM org.datanucleus.enhancer.ClassEnhancerImpl save
INFO: Writing class file "/home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/classes/model/AbstractModel.class" with enhanced definition
May 13, 2015 3:30:07 PM org.datanucleus.enhancer.DataNucleusEnhancer addMessage
INFO: ENHANCED (Persistable) : model.AbstractModel
May 13, 2015 3:30:07 PM org.datanucleus.enhancer.ClassEnhancerImpl save
INFO: Writing class file "/home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/classes/model/Identifier.class" with enhanced definition
May 13, 2015 3:30:07 PM org.datanucleus.enhancer.DataNucleusEnhancer addMessage
INFO: ENHANCED (Persistable) : model.Identifier
May 13, 2015 3:30:07 PM org.datanucleus.enhancer.DataNucleusEnhancer addMessage
INFO: DataNucleus Enhancer completed with success for 2 classes. Timings : input=112 ms, enhance=102 ms, total=214 ms. Consult the log for full details
Enhancer Processing -v.
Enhancer adding Persistence Unit persistence-h2.
Enhancer processing output directory /home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/classes.
Enhancer found JDOEnhancer of class org.datanucleus.api.jdo.JDOEnhancer.
Enhancer property key:VendorName value:DataNucleus.
Enhancer property key:VersionNumber value:4.0.4.
Enhancer property key:API value:JDO.
Enhancer enhanced 2 classes.
Below you can see some debugging information which is passed to Fork.java.fork(...):
=============================================================
mainClass=javax.jdo.Enhancer
args=-v -pu persistence-h2 -d /home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/classes
javaHome=None
cwd=/home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/classes
runJVMOptions=
bootJars ---------------------------------------------
/home/rgomes/.ivy2/cache/org.scala-lang/scala-library/jars/scala-library-2.11.6.jar
/home/rgomes/.ivy2/cache/com.google.code.gson/gson/jars/gson-2.3.1.jar
/home/rgomes/.ivy2/cache/javax.jdo/jdo-api/jars/jdo-api-3.0.jar
/home/rgomes/.ivy2/cache/javax.transaction/transaction-api/jars/transaction-api-1.1.jar
/home/rgomes/.ivy2/cache/org.datanucleus/datanucleus-core/jars/datanucleus-core-4.0.4.jar
/home/rgomes/.ivy2/cache/org.datanucleus/datanucleus-api-jdo/jars/datanucleus-api-jdo-4.0.4.jar
/home/rgomes/.ivy2/cache/org.datanucleus/datanucleus-jdo-query/jars/datanucleus-jdo-query-4.0.4.jar
/home/rgomes/.ivy2/cache/org.datanucleus/datanucleus-rdbms/jars/datanucleus-rdbms-4.0.4.jar
/home/rgomes/.ivy2/cache/com.h2database/h2/jars/h2-1.4.185.jar
/home/rgomes/.ivy2/cache/org.postgresql/postgresql/jars/postgresql-9.4-1200-jdbc41.jar
/home/rgomes/.ivy2/cache/com.github.dblock.waffle/waffle-jna/jars/waffle-jna-1.7.jar
/home/rgomes/.ivy2/cache/net.java.dev.jna/jna/jars/jna-4.1.0.jar
/home/rgomes/.ivy2/cache/net.java.dev.jna/jna-platform/jars/jna-platform-4.1.0.jar
/home/rgomes/.ivy2/cache/org.slf4j/slf4j-simple/jars/slf4j-simple-1.7.7.jar
/home/rgomes/.ivy2/cache/org.slf4j/slf4j-api/jars/slf4j-api-1.7.7.jar
/home/rgomes/workspace/poc-scala-datanucleus/model/src/main/resources
/home/rgomes/workspace/poc-scala-datanucleus/model/target/scala-2.11/klasses
envVars ----------------------------------------------
=============================================================
The project is available in github for your convenience at https://github.com/frgomes/poc-scala-datanucleus
Just download it and type
./sbt compile
Any help is immensely appreciated. Thanks