在dataframe转为rdd
// 造源数据
val data = List( ("Jen","male",18))
val df = spark.createDataFrame(data)
import org.apache.spark.sql.Row
// dataframe转为rdd
val result = df.rdd.map{case Row(name: String, age: Integer) => (name, age)}
result.collect()
报错
Caused by: scala.MatchError: [Jen,male,18] (of class org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema)
问题原因： 字段数量不一致，导致转化类型错误 
改正： 
