小编Viv*_*tty的帖子

星火扔ClassCastExpection在WrappedArray进行任何操作时

示例:我有一个如下所示的地图输出

输出:

Map(1 -> WrappedArray(Pan4), 2 -> WrappedArray(Pan15), 3 -> WrappedArray(Pan16, Pan17, Pan18), 4 -> WrappedArray(Pan19, Pan1, Pan2, Pan3, Pan4, Pan5, Pan6))]

当调用map.values时,其打印输出如下输出

MapLike(WrappedArray(Pan4), WrappedArray(Pan15), WrappedArray(Pan16, Pan17, Pan18), WrappedArray(Pan19, Pan1, Pan2, Pan3, Pan4, Pan5, Pan6))

如果调用map.values.map(arr => arr)或抛出异常map.values.forEach { value => println(value)}

我无法对包装的数组执行任何操作.我只需要每个wrappedArray中存在的元素的大小

Error StackTrace
------------------
java.lang.ClassCastException: scala.collection.mutable.WrappedArray$ofRef cannot be cast to java.util.ArrayList
    at WindowTest$CustomMedian$$anonfun$1.apply(WindowTest.scala:176)
    at WindowTest$CustomMedian$$anonfun$1.apply(WindowTest.scala:176)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
    at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
    at scala.collection.immutable.Map$Map4.foreach(Map.scala:181)
    at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
    at scala.collection.AbstractTraversable.map(Traversable.scala:105)
    at WindowTest$CustomMedian.evaluate(WindowTest.scala:176)
    at org.apache.spark.sql.execution.aggregate.ScalaUDAF.eval(udaf.scala:446)
    at org.apache.spark.sql.execution.aggregate.AggregationIterator$$anonfun$35.apply(AggregationIterator.scala:376)
    at …