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error java.lang.ClassNotFoundException when try to use OneWayAnova Class

I'm using eclipse RCP (helios), and I need to add statistics functions.
In the editor, I have no problem, no error.
But when I run or debug the project, I get:
java.lang.ClassNotFoundException:
org.apache.commons.math3.stat.descriptive.SummaryStatistics error.
first question, the library says si java 1.5+ compatible, I'm running on 1.6.
is this ok?
besides build path... is there any other way to set classpath ?
Best Regards

Intellij not able to run Scala Code

I have a project that uses both Java and Scala code. When I am trying to run a main function from Scala on Intellij 13.1.4 with Scala Plugin 0.38.441 installed I get the following error
Error:scalac: Error: Scala instance doesn't exist or is invalid:
version unknown, library jar: /home/arpit/.m2/repository/org/scala-lang/scala-library/2.11/scala-library-2.11.jar, compiler jar: /home/arpit/.m2/repository/org/scala-lang/scala-compiler/2.11/scala-compiler-2.11.jar
sbt.InvalidScalaInstance: Scala instance doesn't exist or is invalid:
version unknown, library jar: /home/arpit/.m2/repository/org/scala-lang/scala-library/2.11/scala-library-2.11.jar, compiler jar: /home/arpit/.m2/repository/org/scala-lang/scala-compiler/2.11/scala-compiler-2.11.jar
at sbt.ScalaInstance$.slowActualVersion(ScalaInstance.scala:122)
at sbt.ScalaInstance$.sbt$ScalaInstance$$actualVersion(ScalaInstance.scala:119)
at sbt.ScalaInstance$$anonfun$actualVersion$1.apply(ScalaInstance.scala:32)
at sbt.ScalaInstance$$anonfun$actualVersion$1.apply(ScalaInstance.scala:32)
at scala.Option.getOrElse(Option.scala:120)
at sbt.ScalaInstance.actualVersion$lzycompute(ScalaInstance.scala:32)
at sbt.ScalaInstance.actualVersion(ScalaInstance.scala:32)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl$.org$jetbrains$jps$incremental$scala$local$CompilerFactoryImpl$$getOrCompileInterfaceJar(CompilerFactoryImpl.scala:79)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl$$anonfun$getScalac$1.apply(CompilerFactoryImpl.scala:43)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl$$anonfun$getScalac$1.apply(CompilerFactoryImpl.scala:42)
at scala.Option.map(Option.scala:145)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl.getScalac(CompilerFactoryImpl.scala:42)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl.createCompiler(CompilerFactoryImpl.scala:21)
at org.jetbrains.jps.incremental.scala.local.CachingFactory$$anonfun$createCompiler$1.apply(CachingFactory.scala:23)
at org.jetbrains.jps.incremental.scala.local.CachingFactory$$anonfun$createCompiler$1.apply(CachingFactory.scala:23)
at org.jetbrains.jps.incremental.scala.local.Cache$$anonfun$getOrUpdate$2.apply(Cache.scala:20)
at scala.Option.getOrElse(Option.scala:120)
at org.jetbrains.jps.incremental.scala.local.Cache.getOrUpdate(Cache.scala:19)
I also checked for compiler settings under Project setting in IntelliJ and for Scala Compiler it says "Nothing to show here in external build mode". Can this be the problem?

It seems that the compiler cannot read the version of the scala-compiler jar. Maybe it is corrupted. Try to redownload it or to use another version. To set another compiler library go to Project Structure/Facets/Scala facet of your module and select a suitable library.
If it does not work please create a ticket on the bugtracker (with the attached compiler library):
http://youtrack.jetbrains.com/issues/SCL
Also you can try to change the type of the incremental compiler in Settings/IDE Settings/Scala
There is nothing wrong with the Compiler/Scala Compiler settings.

I had the same problem, that's what I've done:
(After installing IntelliJ and SBT) I downloaded Scala as well from this website and installed it.
Then I went to File -> Project Structure -> Libraries and I removed the existing library.
Afterwards, I clicked the "+" symbol and "Scala SDK" and found the Scala installation folder (C:\Program Files (x86)\scala\ in my case).
And followed the instructions. Then everything worked fine...
Hope it helps...

I had similar issue when run Idea under the root user. Idea was not able to find the scala library. I solved the issue by quitting the Idea and run it under my current user.

in my case i went into Compiler/Scala Compiler settings and deleted additional compiler options (make -transitive)

Android project: Conversion to Dalvik format failed with error 1

I am writing an android application using eclipse and am trying to use jar files I generated from another eclipse (not android) project I wrote. However, when I try to run my android application, I get the following error message:
[2014-05-15 18:42:25 - ResearchNotebook] Dx 1 error; aborting
[2014-05-15 18:42:25 - ResearchNotebook] Conversion to Dalvik format failed with error 1
which is preceeded by a longer error message.
I looked at the following question (Ill-advised or mistaken usage of a core class (java.* or javax.*) when not building a core library), and but am not sure how I would reconfigure the eclipse IDE so that rt.jar and android.jar are not being passed to dx.
However, I wrote non android java code within the same project using the jar and ran it in the console. It worked perfectly fine. The problem only arises when I try to use the jar for the classes pertaining to the android application.
At this point, I have tried many different alternatives, including cleaning the project, deleting the jars from the buildpath and adding them again, and changing order and export according to the following site: http://tools.android.com/recent/dealingwithdependenciesinandroidprojects.
Is there something else I should have done when generating the jar from my eclipse (non android) project? I have really hit a wall this problem and am at a loss about how to proceed.

Try the following:
Uncheck "Build Automatically" from the "Project" menu.
Do a project cleanup.
Export your project
Hope it helps.

GWT compilation error in Eclipse

I am struggling hard to compile a GWT project. I confirmed that GWT, AppEngine and necessary library are referenced to the project (added in the Java Build Path, also GWT is installed successfully from Marketplace).
Using the setting above, I tried to build using GWT and I have been getting
java.lang.NoClassDefFoundError: com/google/gwt/dev/Compiler
over and over again.
Then tried to set gwt-dev.jar in Windows CLASSPATH, and I could get off from this error but ended up with
[ERROR] Unable to find 'some/package/My_Project.gwt.xml' on your classpath; could be a typo, or maybe you forgot to include a classpath entry for source?
I tried to set project classpath to some/package/ but didn't work.
Even I could manage to get over with this error for once, again I got into another error:
java.lang.NoClassDefFoundError: com/google/appengine/tools/enhancer/Enhance.
I screwed up the environment and couldn't get to the last error I was getting, and I was just stuck on the second error.
I have tried removing all Run Configuration, creating new workspace and import projects from scratch and tried everything that I found on Google.

Did you look at this answer: GWT/ Eclipse: ClassNotFoundException com/google/gwt/dev/Compiler
Also, you can try to clean your project and add the jar file via the usual class path configuration within eclipse (right click on your project). You can then add the gwt-dev.jar file from the plugin. Make sure you use the one that was installed in the plugin for eclipse.

[ERROR] Unable to find 'some/package/My_Project.gwt.xml' on your
classpath; could be a typo, or maybe you forgot to include a classpath
entry for source?
Check out the link for more info...Here

Problem building a Java Rules app in Eclipse

I'm trying to build a simple Drools project in Eclipse, but when I try to test it, a runtime exception is thrown with the message, "The Eclipse JDT Core jar is not in the classpath."
Any ideas where I might find this jar?
Thanks!

Try this:
http://affy.blogspot.com/2008/07/jboss-rules-classpath-error-eclipse-jdt.html
If it's not that, please provide some more info on your problem...