很新的火花和Scala语言,并希望工会为以下列表中的所有RDDS(List<RDD> to RDD
):星火:我如何工会列表<RDD>到RDD
val data = for (item <- paths) yield {
val ad_data_path = item._1
val ad_data = SparkCommon.sc.textFile(ad_data_path).map {
line => {
val ad_data = new AdData(line)
(ad_data.ad_id, ad_data)
}
}.distinct()
}
val ret = SparkCommon.sc.parallelize(data).reduce(_ ++ _)
我运行代码在IntelliJ中,虽然总是得到一个错误:
ava.lang.NullPointerException
at org.apache.spark.rdd.RDD.<init>(RDD.scala:125)
at org.apache.spark.rdd.UnionRDD.<init>(UnionRDD.scala:59)
at org.apache.spark.rdd.RDD.union(RDD.scala:438)
at org.apache.spark.rdd.RDD.$plus$plus(RDD.scala:444)
at data.GenerateData$$anonfun$load_data$1.apply(GenerateData.scala:99)
at data.GenerateData$$anonfun$load_data$1.apply(GenerateData.scala:99)
at scala.collection.TraversableOnce$$anonfun$reduceLeft$1.apply(TraversableOnce.scala:177)
at scala.collection.TraversableOnce$$anonfun$reduceLeft$1.apply(TraversableOnce.scala:172)
at scala.collection.Iterator$class.foreach(Iterator.scala:727)
at org.apache.spark.InterruptibleIterator.foreach(InterruptibleIterator.scala:28)
at scala.collection.TraversableOnce$class.reduceLeft(TraversableOnce.scala:172)
at org.apache.spark.InterruptibleIterator.reduceLeft(InterruptibleIterator.scala:28)
at org.apache.spark.rdd.RDD$$anonfun$18.apply(RDD.scala:847)
at org.apache.spark.rdd.RDD$$anonfun$18.apply(RDD.scala:845)
at org.apache.spark.SparkContext$$anonfun$26.apply(SparkContext.scala:1157)
at org.apache.spark.SparkContext$$anonfun$26.apply(SparkContext.scala:1157)
at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:62)
at org.apache.spark.scheduler.Task.run(Task.scala:54)
at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:177)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
任何人有任何关于错误的想法吗?感谢提前:)
非常感谢,所述您的解决方案解决了问题。 – juffun
@juffun,可以接受答案,如果解决方案为你工作:) – Akash
当然,已经接受。 – juffun