当我使用一个简单的foreach并在Dataframe上迭代时，spark给了我classnotfoundexception。我很困惑，因为它正确地返回了输入Dataframe。但是我不能在它上迭代。可能是什么问题？
我的代码：

import scala.collection.Iterable
import org.apache.spark.sql.Dataset
import org.apache.spark.sql.Row
import org.apache.spark.sql.SparkSession
import scala.collection.mutable._

object Script {
  def execute(spark: SparkSession,
              input: Iterable[Dataset[Row]]): Dataset[Row] = {
        import spark.implicits._
        val input=spark.table("input")
        input.foreach(r => println(r))
        input
  }
}

错误：

java.lang.ClassNotFoundException: $line14.$read$$iw$$iw$Script$2$$anonfun$execute$1
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at org.apache.spark.serializer.JavaDeserializationStream$$anon$1.resolveClass(JavaSerializer.scala:67)
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1925)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2099)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1625)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2344)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2268)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2126)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1625)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2344)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2268)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2126)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1625)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2344)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2268)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2126)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1625)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:465)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:423)
    at org.apache.spark.serializer.JavaDeserializationStream.readObject(JavaSerializer.scala:75)
    at org.apache.spark.serializer.JavaSerializerInstance.deserialize(JavaSerializer.scala:114)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:83)
    at org.apache.spark.scheduler.Task.run(Task.scala:123)
    at org.apache.spark.executor.Executor$TaskRunner$$anonfun$10.apply(Executor.scala:408)
    at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1405)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:414)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)