Question

这个演示运行正常。但是当我将它移动到另一个类函数（我以前的项目）并调用该函数时，它会编译失败。

     object DFMain {
         case class Person(name: String, age: Double, t:String)
         def main (args: Array[String]): Unit = {
         val sc = new SparkContext("local", "Scala Word Count")
         val sqlContext = new org.apache.spark.sql.SQLContext(sc)
         import sqlContext.implicits._
         val bsonRDD = sc.parallelize(("foo",1,"female")::
                                        ("bar",2,"male")::
                                     ("baz",-1,"female")::Nil)
                      .map(tuple=>{
                    var bson = new BasicBSONObject()
                    bson.put("name","bfoo")
                    bson.put("value",0.1)
                    bson.put("t","female")
                    (null,bson)
                 })
    val tDf = bsonRDD.map(_._2)
              .map(f=>Person(f.get("name").toString,
                   f.get("value").toString.toDouble,
                   f.get("t").toString)).toDF()

       tDf.limit(1).show()
 }
}

'MySQLDao.insertIntoMySQL（）'编译错误

object MySQLDao {
     private val sc= new SparkContext("local", "Scala Word Count")
     val sqlContext = new org.apache.spark.sql.SQLContext(sc)
     import sqlContext.implicits._

     case class Person(name: String, age: Double, t:String)
     def insertIntoMySQL(): Unit ={

      val bsonRDD = sc.parallelize(("foo",1,"female")::
                                     ("bar",2,"male")::
                                     ("baz",-1,"female")::Nil)
                       .map(tuple=>{
               val bson = new BasicBSONObject()
               bson.put("name","bfoo")
               bson.put("value",0.1)
               bson.put("t","female")
               (null,bson)
         })
 val tDf = bsonRDD.map(_._2).map( f=> Person(f.get("name").toString,
                                           f.get("value").toString.toDouble,
                                            f.get("t").toString)).toDF()

   tDf.limit(1).show()

 }
}

当我调用'MySQLDao.insertIntoMySQL（）'时会出现错误

value typedProductIterator不是对象scala.runtim.scala.scalaRuntTime的成员

case class Person（name：String，age：Double，t：String）

Answer 1

我认为在map函数中的闭包中没有看到case类。将其移至包级别。

case class Person(name: String, age: Double, t:String)
object MySQLDao {
...
}

Scala：case类runTime错误

1 个答案: