saveTocassandra找不到参数rwf的隐含值

Question

I'm trying to save a dataset in Cassandra database using spark scala, But I am getting an exception while running a code: link used: http://rustyrazorblade.com/2015/01/introduction-to-spark-cassandra/

error:

could not find implicit value for parameter rwf: com.datastax.spark.connector.writer.RowWriterFctory[FoodToUserIndex]
 food_index.saveToCassandra("tutorial", "food_to_user_index")
                          ^

.scala

def main(args: Array[String]): Unit = {

val conf = new SparkConf(true)
  .set("spark.cassandra.connection.host", "localhost")
  .set("spark.executor.memory", "1g")
  .set("spark.cassandra.connection.native.port", "9042")
val sc = new SparkContext(conf)


case class FoodToUserIndex(food: String, user: String)

val user_table = sc.cassandraTable[CassandraRow]("tutorial",   "user").select("favorite_food","name")

val food_index = user_table.map(r => new   FoodToUserIndex(r.getString("favorite_food"), r.getString("name")))
food_index.saveToCassandra("tutorial", "food_to_user_index")}

build.sbt

name := "intro_to_spark"

version := "1.0"

scalaVersion := "2.11.2"

libraryDependencies += "org.apache.spark" %% "spark-core" % "1.2.0"

libraryDependencies += "com.datastax.spark" %% "spark-cassandra-connector" %  "1.2.0-rc3"

if change the version of scala and cassandra connector to 2.10, 1.1.0 it's work. but i need use scala 2.11:

scalaVersion := "2.10.4"

libraryDependencies += "org.apache.spark" %% "spark-core" % "1.2.0"

libraryDependencies += "com.datastax.spark" %% "spark-cassandra-connector" %   "1.1.0" withSources() withJavadoc()

Answer 1

移动case class FoodToUserIndex(food: String, user: String)在main函数之外应该解决问题。

Answer 2

It has to do with "datastax spark-cassandra-connector" version and not Scala version.

So far, Version 1.2.x missing saving from custom class.

Try "datastax spark-cassandra-connector" version 1.1.1 with Scala 2.11 and it should work

Note: Make sure to have Spark compiled against Scala 2.11 too.