如何在Scala dataframe中获取列的数据类型

import org.apache.spark.sql.{SparkSession, DataFrame}

val spark = SparkSession.builder()
  .appName("Get column data types")
  .master("local")
  .getOrCreate()

val data = Seq(
  (1, "John", 25),
  (2, "Jane", 30),
  (3, "Bob", 35)
)

val df: DataFrame = spark.createDataFrame(data).toDF("id", "name", "age")

val columnTypes = df.dtypes

columnTypes.foreach { case (columnName, dataType) =>
  println(s"Column $columnName has data type $dataType")
}

Column id has data type IntegerType
Column name has data type StringType
Column age has data type IntegerType