I'm doing my first steps with maven and scala. I'm starting with a single Scala Application that i can launch with the scala:run command.
I created the standard scala maven archetype with "mvn archetype:generate", choosing
"30: internal -> scala-archetype-simple (A simple scala project)".
Then i inserted a launcher into my pom.xml, that should start the App that was generated by maven (i just use the app created by the archetype):
<launchers>
<launcher>
<id>myLauncher</id>
<mainClass>myapp.App</mainClass>
</launcher>
</launchers>
When i launch this Project with "mvn scala:run", everything works fine - no errors, and i get my "Hello World" in the maven output.
Now i want to switch to scala version 2.8. So i changed the scala version in my pom.xml to 2.8.0-SNAPSHOT, resulting in the following pom.xml (see below).
Now compiling with "mvn compile" command fails with an error like "java.lang.IncompatibleClassChangeError: Found class scala.collection.JavaConversions$JMapWrapperLike, but interface was expected" (complete maven output see below), and "mvn scala:run" also fails (complete output see below).
Anyone got any idea about it? Could'nt find anything in the web about it. Are there incompatibility issues with scala2.8 and the maven plugin?
pom.xml
<project xmlns="[maven.apache.org]; xmlns:xsi="[www.w3.org]; xsi:schemaLocation="[maven.apache.org] [maven.apache.org];
<modelVersion>4.0.0</modelVersion>
<groupId>maventest</groupId>
<artifactId>version1</artifactId>
<version>1.0-SNAPSHOT</version>
<inceptionYear>2008</inceptionYear>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<!-- run fails with 2.8 -->
<scala.version>2.8.0-SNAPSHOT</scala.version>
<!-- build runs successfully when using 2.7.7
<scala.version>2.7.7</scala.version>
-->
</properties>
<repositories>
<repository>
<id>scala-tools.org</id>
<name>Scala-Tools Maven2 Repository</name>
<url>[scala-tools.org];
</repository>
<!-- For Scala 2.8 -->
<repository>
<id>scala-tools.snapshot</id>
<name>Scala-Tools Snapshot Repository</name>
<url>[scala-tools.org];
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>scala-tools.org</id>
<name>Scala-Tools Maven2 Repository</name>
<url>[scala-tools.org];
</pluginRepository>
</pluginRepositories>
<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${scala.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.4</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.specs</groupId>
<artifactId>specs</artifactId>
<version>1.2.5</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
<configuration>
<launchers>
<launcher>
<id>myLauncher</id>
<mainClass>maventest.App</mainClass>
</launcher>
</launchers>
<scalaVersion>${scala.version}</scalaVersion>
<args>
<arg>-target:jvm-1.5</arg>
</args>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<configuration>
<downloadSources>true</downloadSources>
<buildcommands>
<buildcommand>ch.epfl.lamp.sdt.core.scalabuilder</buildcommand>
</buildcommands>
<additionalProjectnatures>
<projectnature>ch.epfl.lamp.sdt.core.scalanature</projectnature>
</additionalProjectnatures>
<classpathContainers>
<classpathContainer>org.eclipse.jdt.launching.JRE_CONTAINER</classpathContainer>
<classpathContainer>ch.epfl.lamp.sdt.launching.SCALA_CONTAINER</classpathContainer>
</classpathContainers>
</configuration>
</plugin>
</plugins>
</build>
<reporting>
<plugins>
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<configuration>
<scalaVersion>${scala.version}</scalaVersion>
</configuration>
</plugin>
</plugins>
</reporting>
</project>
mvn compile output:
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Unnamed - maventest:version1:jar:1.0-SNAPSHOT
[INFO] task-segment: [compile]
[INFO] ------------------------------------------------------------------------
[INFO] [resources:resources {execution: default-resources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\Workspace\Scala\MavenTest\src\main\resources
[INFO] [compiler:compile {execution: default-compile}]
[INFO] Nothing to compile - all classes are up to date
[INFO] [scala:compile {execution: default}]
[INFO] Checking for multiple versions of scala
[INFO] includes = [**/*.scala,**/*.java,]
[INFO] excludes = []
[INFO] D:\Workspace\Scala\MavenTest\src\main\scala:-1: info: compiling
[INFO] Compiling 1 source files to D:\Workspace\Scala\MavenTest\target\classes at 1268744610450
[INFO] java.lang.reflect.InvocationTargetException
[INFO] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[INFO] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[INFO] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[INFO] at java.lang.reflect.Method.invoke(Method.java:597)
[INFO] at org_scala_tools_maven_executions.MainHelper.runMain(MainHelper.java:151)
[INFO] at org_scala_tools_maven_executions.MainWithArgsInFile.main(MainWithArgsInFile.java:26)
[ERROR] Caused by: java.lang.IncompatibleClassChangeError: Found class scala.collection.JavaConversions$JMapWrapperLike, but interface was expected
[INFO] at scala.tools.nsc.symtab.Types$CompoundType.memo(Types.scala:1259)
[INFO] at scala.tools.nsc.symtab.Types$CompoundType.baseClasses(Types.scala:1251)
[INFO] at scala.tools.nsc.symtab.Types$Type.findMember(Types.scala:817)
[INFO] at scala.tools.nsc.symtab.Types$Type.member(Types.scala:468)
[INFO] at scala.tools.nsc.symtab.Definitions$definitions$.getModuleOrClass(Definitions.scala:505)
[INFO] at scala.tools.nsc.symtab.Definitions$definitions$.ScalaPackage(Definitions.scala:43)
[INFO] at scala.tools.nsc.symtab.Definitions$definitions$.ScalaPackageClass(Definitions.scala:44)
[INFO] at scala.tools.nsc.symtab.Definitions$definitions$.UnitClass(Definitions.scala:86)
[INFO] at scala.tools.nsc.symtab.Definitions$definitions$.init(Definitions.scala:767)
[INFO] at scala.tools.nsc.Global$Run.<init>(Global.scala:591)
[INFO] at scala.tools.nsc.Main$.process(Main.scala:108)
[INFO] at scala.tools.nsc.Main$.main(Main.scala:123)
[INFO] at scala.tools.nsc.Main.main(Main.scala)
[INFO] ... 6 more
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] wrap: org.apache.commons.exec.ExecuteException: Process exited with an error: -2147483648(Exit value: -2147483648)
[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4 seconds
[INFO] Finished at: Tue Mar 16 14:03:31 CET 2010
[INFO] Final Memory: 14M/26M
[INFO] ------------------------------------------------------------------------
mvn scala:run output:
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Building Unnamed - maventest:version1:jar:1.0-SNAPSHOT
[INFO] task-segment: [scala:run]
[INFO] ------------------------------------------------------------------------
[INFO] Preparing scala:run
[INFO] [resources:resources {execution: default-resources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\Workspace\Scala\MavenTest\src\main\resources
[INFO] [compiler:compile {execution: default-compile}]
[INFO] Nothing to compile - all classes are up to date
[INFO] [scala:compile {execution: default}]
[INFO] Checking for multiple versions of scala
[INFO] Nothing to compile - all classes are up to date
[INFO] [resources:testResources {execution: default-testResources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\Workspace\Scala\MavenTest\src\test\resources
[INFO] [compiler:testCompile {execution: default-testCompile}]
[INFO] Nothing to compile - all classes are up to date
[INFO] [scala:testCompile {execution: default}]
[INFO] Checking for multiple versions of scala
[INFO] Nothing to compile - all classes are up to date
[INFO] [scala:run {execution: default-cli}]
[INFO] Checking for multiple versions of scala
[INFO] launcher 'myLauncher' selected => maventest.App
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org_scala_tools_maven_executions.MainHelper.runMain(MainHelper.java:151)
at org_scala_tools_maven_executions.MainWithArgsInFile.main(MainWithArgsInFile.java:26)
Caused by: java.lang.AbstractMethodError: maventest.App$.scala$Application$_setter_$executionStart_$eq(J)V
at scala.Application$class.$init$(Application.scala:79)
at maventest.App$.<init>(App.scala:7)
at maventest.App$.<clinit>(App.scala)
at maventest.App.main(App.scala)
... 6 more
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] wrap: org.apache.commons.exec.ExecuteException: Process exited with an error: -2147483648(Exit value: -2147483648)
[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3 seconds
[INFO] Finished at: Tue Mar 16 13:51:19 CET 2010
[INFO] Final Memory: 13M/27M
[INFO] ------------------------------------------------------------------------
My App:
package maventest
object App extends Application {
println( "Hello World!" )
}
]]>