如何在spark join过程中选择动态列？

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

// 定义函数来选择连接的列
def selectJoinColumn(condition: Boolean, column1: String, column2: String): String = {
  if (condition) column1 else column2
}

// 创建DataFrame
val df1 = spark.createDataFrame(Seq((1, "A"), (2, "B"), (3, "C"))).toDF("id", "value1")
val df2 = spark.createDataFrame(Seq((1, "X"), (2, "Y"), (3, "Z"))).toDF("id", "value2")

// 添加一个新的列，根据条件选择连接的列
val joinColumn = selectJoinColumn(true, "id", "value1")
val joinedDF = df1.withColumn("joinColumn", lit(joinColumn)).join(df2, Seq("joinColumn"))

// 显示结果
joinedDF.show()