Caused by: java.lang.UnsupportedOperationException: fieldIndex on a Row without schema is undefined.
at org.apache.spark.sql.Row$class.fieldIndex(Row.scala:342)
at org.apache.spark.sql.catalyst.expressions.GenericRow.fieldIndex(rows.scala:166)
at org.apache.spark.sql.Row$class.getAs(Row.scala:333)
at org.apache.spark.sql.catalyst.expressions.GenericRow.getAs(rows.scala:166)
at wf.Test2.lambda$main$8194cff9$1(Test2.java:54)
at org.apache.spark.sql.Dataset$$anonfun$45.apply(Dataset.scala:2705)
at org.apache.spark.sql.Dataset$$anonfun$45.apply(Dataset.scala:2705)
at scala.collection.Iterator$$anon$12.nextCur(Iterator.scala:435)
at scala.collection.Iterator$$anon$12.hasNext(Iterator.scala:441)
at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:409)
at org.apache.spark.sql.catalyst.expressions.GeneratedClass$
