如何在使用spark写入拼图文件时添加额外的元数据

import org.apache.spark.sql._
import org.apache.spark.sql.functions._
import org.apache.spark.sql.types._

val spark = SparkSession.builder()
  .appName("Add Metadata to Parquet File")
  .getOrCreate()

val data = spark.read.parquet("path/to/input/file.parquet")
val df = spark.createDataFrame(data.rdd, data.schema)

val metadata = Map("key1" -> "value1", "key2" -> "value2")

val dfWithMetadata = df.withColumn("metadata", typedLit(metadata))

dfWithMetadata.write
  .option("mergeSchema", "true")
  .parquet("path/to/output/file.parquet")