使用Scala配置Play框架以使用Neo4j图形数据库

Question

I'm using scala in my app, it run without problem, but if I add neo4j in the dependencies, it throws a NoSuchMethod error. I didn't even have references to any neo4j classes in my code...

I have no problem using play framework with scala, or play framework (Java) with neo4j, just when using both together, it crash...

and I tried both neo4j 1.4.2 and 1.5.M02 to no avail.

thanks for any help~

Chris

dependencies.yml

# Application dependencies

require:
- play
- play -> scala 0.9.1
- org.neo4j -> neo4j 1.4.2

exception details:

play.exceptions.UnexpectedException: Unexpected Error
    at play.Invoker$Invocation.onException(Invoker.java:232)
    at play.Invoker$Invocation.run(Invoker.java:273)
    at Invocation.HTTP Request(Play!)
Caused by: java.lang.NoSuchMethodError: scala.collection.generic.GenericTraversableTemplate.flatten(Lscala/Function1;)Lscala/collection/Traversable;
    at play.scalasupport.compiler.PlayScalaCompiler$.scanFiles(ScalaCompiler.scala:18)
    at play.scalasupport.compiler.PlayScalaCompiler$$anonfun$scanFiles$1.apply(ScalaCompiler.scala:17)
    at play.scalasupport.compiler.PlayScalaCompiler$$anonfun$scanFiles$1.apply(ScalaCompiler.scala:15)
    at play.scalasupport.compiler.PlayScalaCompiler$.scanFiles(ScalaCompiler.scala:15)
    at play.scalasupport.compiler.PlayScalaCompiler$$anonfun$scanFiles$1.apply(ScalaCompiler.scala:17)
    at play.scalasupport.compiler.PlayScalaCompiler$$anonfun$scanFiles$1.apply(ScalaCompiler.scala:15)
    at play.scalasupport.compiler.PlayScalaCompiler$.scanFiles(ScalaCompiler.scala:15)
    at play.scalasupport.ScalaPlugin$$anonfun$templates$1.apply(ScalaPlugin.scala:178)
    at play.scalasupport.ScalaPlugin$$anonfun$templates$1.apply(ScalaPlugin.scala:177)
    at play.scalasupport.ScalaPlugin.templates(ScalaPlugin.scala:177)
    at play.scalasupport.ScalaPlugin.update(ScalaPlugin.scala:195)
    at play.scalasupport.ScalaPlugin.detectClassesChange(ScalaPlugin.scala:107)
    at play.plugins.PluginCollection.detectClassesChange(PluginCollection.java:358)
    at play.Play.detectChanges(Play.java:594)
    at play.Invoker$Invocation.init(Invoker.java:186)
    ... 1 more

Answer 1

it turns out that scala-library-2.9.0-1.jar is included as a dependency for neo4j...

every time I run play dependencies it will be downloaded into the lib folder, after I delete it from the folder, it works without problem (so far I just have code for starting and shutting down of the DB).

Answer 2

The Cypher Query language depends on Scala. We will update that dependency to 2.9.1 for the 1.5 release.