Hi All,
I'm relatively new to Scala, but I've run into this issue a couple of times. The first time, only my Coursera grade was at stake, but this time I'm trying to do some real work :).
I believe that the error may relate to doing reactive programming in Scala, as both situations employ reactive code. The code I'm using, aside from my build system, was copied directly from the
Twitter-Server page, so I don't think it is an obvious programming error. Maybe a build system issue?
Steps to reproduce:
git clone https://github.com/bbarker/TwitterServerTest.git
cd TwitterServerTest/
gradle build
gradle copyToLib
cd build/libs/
scala -cp ./*.jar edu.cornell.comm.twitter.server.Basic
Server
java.lang.NullPointerException
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at scala.reflect.internal.util.ScalaClassLoader$$anonfun$tryClass$1.apply(ScalaClassLoader.scala:43)
at scala.reflect.internal.util.ScalaClassLoader$$anonfun$tryClass$1.apply(ScalaClassLoader.scala:43)
at scala.util.control.Exception$Catch$$anonfun$opt$1.apply(Exception.scala:119)
at scala.util.control.Exception$Catch$$anonfun$opt$1.apply(Exception.scala:119)
at scala.util.control.Exception$Catch.apply(Exception.scala:103)
at scala.util.control.Exception$Catch.opt(Exception.scala:119)
at scala.reflect.internal.util.ScalaClassLoader$class.tryClass(ScalaClassLoader.scala:42)
at scala.reflect.internal.util.ScalaClassLoader$class.tryToInitializeClass(ScalaClassLoader.scala:39)
at scala.reflect.internal.util.ScalaClassLoader$URLClassLoader.tryToInitializeClass(ScalaClassLoader.scala:101)
at scala.reflect.internal.util.ScalaClassLoader$class.run(ScalaClassLoader.scala:63)
at scala.reflect.internal.util.ScalaClassLoader$URLClassLoader.run(ScalaClassLoader.scala:101)
at scala.tools.nsc.CommonRunner$class.run(ObjectRunner.scala:22)
at scala.tools.nsc.JarRunner$.run(MainGenericRunner.scala:13)
at scala.tools.nsc.CommonRunner$class.runAndCatch(ObjectRunner.scala:29)
at scala.tools.nsc.JarRunner$.runJar(MainGenericRunner.scala:25)
at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:69)
at scala.tools.nsc.MainGenericRunner.run$1(MainGenericRunner.scala:87)
at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:98)
at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:103)
at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)
I've tested this on both Cygwin64 and Linux64, so it seems to not be a platform issue. I've also tested using Gradle 2.3 and 2.4.
Thanks in advance for any suggestions or insights.