Add file name as Spark DataFrame column

DataFrameWithFileName.scala

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

object DataFrameWithFileNameApp extends App {
  
  val spark: SparkSession =
    SparkSession
      .builder()
      .appName("DataFrameApp")
      .config("spark.master", "local[*]")
      .getOrCreate()

  val csvFileDF = spark.read.format("csv")
    .option("header", "true")
    .option("delimiter", ",")
    .load("""src/test/resources/csv/emp.csv""")

  spark.udf.register("get_file_name", (path: String) => path.split("/").last.split("\\.").head)

  csvFileDF.withColumn("fileName", callUDF("get_file_name", input_file_name())).show()


  spark.close()

}
//emp.csv
id,name,age,salary
1,jon,26,12.2
2,sam,29,24.4
3,rom,21,2.5


<=============output============>
+---+----+---+------+--------+
| id|name|age|salary|fileName|
+---+----+---+------+--------+
|  1| jon| 26|  12.2|     emp|
|  2| sam| 29|  24.4|     emp|
|  3| rom| 21|   2.5|     emp|
+---+----+---+------+--------+

//sbt dependecies 
libraryDependencies ++= Seq(
  "org.apache.spark" %% "spark-sql" % "2.1.0"
)