Exception in thread "main" java.lang.NoSuchMethodError: org.apache.spark.sql.SQLContext.sql(Ljava/lang/String;)Lorg/apache/spark/sql/Dataset; 버전 문제로 에러가 난듯 함. 설치되어 있는 Spark 버전은 1.6.1 이였는데, libraryDependencies ++= Seq("org.apache.spark" %% "spark-core" % "1.6.1","org.apache.spark" %% "spark-mllib" % "1.6.1","org.apache.spark" %% "spark-sql" % "1.6.1","org.apache.spark" %% "spark-hive" % "1.6.1") ..