Error creating dataframes in spark

Question

I am trying to create a dataframe in kafka-spark stream , i have successfuly mapped values to case class, but whenever i call toDF method it gives me error. **

value toDF is not a member of Array[WeatherEvent] [error] possible cause: maybe a semicolon is missing before `value toDF'? [error]
}).toDF("longitude", "latitude", "country", "sunrise", "sunset", "temperature", "temperatureMin", "temperatureMax", [error] ^ [error] one error found [error] (compile:compileIncremental) Compilation failed [error] Total time: 2 s, completed Sep 27, 2017 11:49:23 AM

Here is my code

 val inputStream = KafkaUtils.createDirectStream(ssc, PreferConsistent, Subscribe[String, String ](Array("test"), kafkaParams))
 //  val json = parse(inputStream)


  val processedStream = inputStream
  .flatMap(record => record.value.split(" ").map(payload => {
        //val ts = Timestamp.valueOf(payload(3))
        WeatherEvent(payload(0).toDouble, payload(1).toDouble, payload(2).toString , payload(3).toInt,
                    payload(4).toInt, payload(5).toDouble, payload(6).toDouble, payload(7).toDouble, 
                    payload(8).toDouble, payload(9).toInt, payload(10).toInt, payload(11).toInt, 
                    payload(12).toDouble, payload(13).toDouble)
      }).toDF("longitude", "latitude", "country", "sunrise", "sunset", "temperature", "temperatureMin", "temperatureMax", 
              "pressure", "humidity", "cloudiness", "id", "wind_speed", "wind_deg")
 )

Thanks **

user_4029265 · Answer

toDF() is an implicit method defined in sqlContext. toDF() is used to convert an RDD to Dataframe. Here you are getting a stream from Kafka I mean Dstreams. To convert the same to DF, you need to process each RDD in the Dstreams either using transform API or foreachRDD API. Below I am using foreachRDD transformation to convert RDD to Dataframe

val data=KafkaUtils.createStream(ssc, zkQuorum, "GroupName", topics).map(x=>x._2)
val lines12=data.foreachRDD(x=>{
  val df=x.flatMap(x => x.split(",")).map(x=>(x(0),x(1))).toDF()
}

Error creating dataframes in spark

1 Answers