Small number causes java.lang.ClassCastException when snakeyaml deserialized object is passed to Gatling feeder - scala

Question

I'm running a gatling simulation that uses numeric input from a yml file to feed its scenario. Everything works when my numeric inputs are large enough that they cannot be parsed as instances of java.lang.Integer, but small numeric values are apparently parsed to Integers and result in a ClassCastException.
import java.io.FileInputStream
import io.gatling.core.Predef.{Feeder, Simulation}
import org.yaml.snakeyaml.Yaml
import org.yaml.snakeyaml.constructor.Constructor
import io.gatling.core.Predef.{scenario, _}
import scala.collection.JavaConversions
class TestClass extends Simulation {
val yaml = new Yaml(new Constructor(classOf[Holder]))
val holder = yaml.load(new FileInputStream("src/test/resources/data.yml")).asInstanceOf[Holder]
scenario("sim").feed(getUserEmulationFeeder(holder))
def getUserEmulationFeeder(holder:Holder) : Feeder[Long] = {
val iterable = JavaConversions.iterableAsScalaIterable(holder.numbers)
iterable.map(l => Map("userToEmulate" -> l)).iterator
}
}
data.yml has the following data:
numbers:
- 30687965369
- 31415388869
- 2
and is being deserialized into:
import scala.beans.BeanProperty
class Holder {
#BeanProperty var numbers = new java.util.ArrayList[Long]()
}
Removing the 2 fixes the ClassCastException.
The full stacktrace is:
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at io.gatling.mojo.MainWithArgsInFile.runMain(MainWithArgsInFile.java:50)
at io.gatling.mojo.MainWithArgsInFile.main(MainWithArgsInFile.java:33)
Caused by: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Long
at scala.runtime.BoxesRunTime.unboxToLong(BoxesRunTime.java:105)
at com.mercurygate.TestClass$$anonfun$getUserEmulationFeeder$1.apply(TestClass.scala:25)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.Iterator$class.foreach(Iterator.scala:893)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1336)
at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
at scala.collection.AbstractIterable.foreach(Iterable.scala:54)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
at scala.collection.AbstractTraversable.map(Traversable.scala:104)
at com.mercurygate.TestClass.getUserEmulationFeeder(TestClass.scala:25)
at com.mercurygate.TestClass.<init>(TestClass.scala:21)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.lang.Class.newInstance(Class.java:442)
at io.gatling.app.Gatling$.io$gatling$app$Gatling$$$anonfun$1(Gatling.scala:41)
at io.gatling.app.Gatling$lambda$1.apply(Gatling.scala:41)
at io.gatling.app.Gatling$lambda$1.apply(Gatling.scala:41)
at io.gatling.app.Gatling.run(Gatling.scala:92)
at io.gatling.app.Gatling.runIfNecessary(Gatling.scala:75)
at io.gatling.app.Gatling.start(Gatling.scala:65)
at io.gatling.app.Gatling$.start(Gatling.scala:57)
at io.gatling.app.Gatling$.fromArgs(Gatling.scala:49)
at io.gatling.app.Gatling$.main(Gatling.scala:43)
at io.gatling.app.Gatling.main(Gatling.scala)
... 6 more
P.S. Sorry for the complexity of the example. It's only when I combine snakeyaml, gatling, and the small input that I get the error.