Remove keys from output files in spark

E.g.

package test   import com.cotdp.hadoop.ZipFileInputFormat import org.apache.hadoop.io.{BytesWritable, NullWritable, Text} import org.apache.hadoop.mapred.lib.MultipleTextOutputFormat import org.apache.spark.sql.SparkSession   class RDDMultipleTextOutputFormat extends MultipleTextOutputFormat[Any, Any] {   override def generateActualKey(key: Any, value: Any): Any =     NullWritable.get() }   object test {   def main(args: Array[String]): Unit = {     val spark = SparkSession.builder().appName("test").getOrCreate()       val zipFileRDD = spark.sparkContext.newAPIHadoopFile("/tmp/spark", classOf[ZipFileInputFormat],       classOf[Text],       classOf[BytesWritable],       spark.sparkContext.hadoopConfiguration)       println("The file name in the zipFile is: " + zipFileRDD.map(s => s._1.toString).first)     println("The file contents are: " + zipFileRDD.map(s => new String(s._2.getBytes, "UTF-8")).first)       zipFileRDD.map(s => (s._1.toString, new String(s._2.getBytes, "UTF-8"))).saveAsHadoopFile("/tmp/test/zip2", classOf[String], classOf[String], classOf[RDDMultipleTextOutputFormat])     spark.stop()   } }