在spark scala中动态创建CSV文件头

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

val spark = SparkSession.builder()
  .appName("Dynamic CSV Header")
  .getOrCreate()

val data = Seq(
  ("John", 25, "USA"),
  ("Alice", 30, "Canada"),
  ("Bob", 35, "UK")
)
val df = spark.createDataFrame(data).toDF("Name", "Age", "Country")

val header = df.columns.mkString(",") // 获取DataFrame的列名并用逗号拼接
val headerDF = spark.createDataFrame(Seq(header)).toDF("header") // 创建只包含一个列的DataFrame
val finalDF = headerDF.union(df) // 将headerDF和原始DataFrame合并

finalDF.write
  .option("header", "false") // 不写入CSV文件头
  .csv("path/to/output.csv")