Scala：在RDD映射中不可序列化的任务由json4s引起“隐式val格式= DefaultFormats”

以下程序尝试为每个ROW调用3个函数（在RDD映射中）：

import org.json4s._
    import org.json4s.jackson.JsonMethods._
    implicit val formats = DefaultFormats

    class TagCalculation extends Serializable {
    def test1(x: String) = x + " test1"
    def test2(x: String) = x + "test2" 
    def test3(x: String) = x + "test3" 
    def test5(arg1: java.lang.Integer, arg2: String, arg3: scala.collection.immutable.$colon$colon[Any]) = "test mix2"
  }
  val df = sqlContext.createDataFrame(Seq((1,"Android"), (2, "iPhone")))
  val get_test = new TagCalculation
  val field = Array("test1","test2","test3")

  val bb = df.rdd.map(row => {

    val reValue1 = "start"
    val ret = for(every <- field)
      yield {
        val test_para = Array(reValue1)
        val argtypes = test_para.map(_.getClass)
        val method4 = get_test.getClass.getMethod(every, argtypes: _*)

        val bbq = method4.invoke(get_test, test_para: _*)

        if (field.last == every)
            bbq
      }
    ret.last
  })

但有些错误输出：

org.apache.spark.SparkException：org.apache.spark.util.ClosureCleaner $ .ensureSerializable（ClosureCleaner.scala：304）org.apache.spark.util.ClosureCleaner $ .org $ apache $ spark $的任务不可序列化util $ ClosureCleaner $$ clean（ClosureCleaner.scala：294）atg.apache.spark.util.ClosureCleaner $ .clean（ClosureCleaner.scala：122）at org.apache.spark.SparkContext.clean（SparkContext.scala：2032）在org.apache.spark.rdd.RDD $$ anonfun $ map $ 1.apply（RDD.scala：314）at org.apache.spark.rdd.RDD $$ anonfun $ map $ 1.apply（RDD.scala：313） org.apache.spark.rdd.RDDOperationScope $ .withScope（RDDOperationScope.scala：147）atg.apache.spark.rdd.RDDOperationScope $ .withScope（RDDOperationScope.scala：108）at org.apache.spark.rdd.RDD .withScope（RDD.scala：306）atg.apache.spark.rdd.RDD.map（RDD.scala：313）........ org.apache.spark.deploy.SparkSubmit $ .submit（ SparkSubmit.scala：205）atg.apache.spark.deploy.SparkSubmit $ .main（SparkSubmit.scala：120）at org.apache.spark.deploy.SparkSubmit.main（SparkSubmit.scala）引起by：java.io.NotSerializableException：org.json4s.DefaultFormats $

有什么指针吗？

它可能是由“隐式val格式= DefaultFormats”引起的 . 但我需要在“ Map ”之前提取 Value .