你不能打电话 LocalDateTime 在Spark柱上。您需要使用spark sql方法：

import java.sql.Timestamp
import java.time.{LocalDateTime, ZoneOffset}
import java.time.format.DateTimeFormatter
import org.apache.spark.sql.functions._

val tempdf = Seq(Timestamp.valueOf(LocalDateTime.of(2021, 3, 8, 18, 0))).toDF("Date1")

tempdf.withColumn("newDate", 
    to_date(
        concat_ws("-",
            year(add_months($"Date1",-1)),
            month(add_months($"Date1",-1)),
            lit(1)
        )
    )
).show()

+-------------------+----------+
|              Date1|   newDate|
+-------------------+----------+
|2021-03-08 18:00:00|2021-02-01|
+-------------------+----------+

更整洁的方法是使用 trunc :

tempdf.withColumn("newDate", add_months(trunc($"Date1", "month"), -1)).show()
+-------------------+----------+
|              Date1|   newDate|
+-------------------+----------+
|2021-03-08 18:00:00|2021-02-01|
+-------------------+----------+