Wordcount program using Spark Streaming

import org.apache.spark._
import org.apache.spark.streaming._
import org.apache.spark.streaming.StreamingContext._
import org.apache.log4j.Logger
import org.apache.log4j.Level

// we are going to reconfigure SparkConfiguration so, we stop existing SparkContext

 sc.stop
 Logger.getLogger("org").setLevel(Level.OFF)
 Logger.getLogger("akka").setLevel(Level.OFF)

 val conf = new SparkConf().setMaster("local[4]").setAppName("workdcount")
 val ssc = new StreamingContext(conf,Seconds(30))
 val data = ssc.socketTextStream("localhost",7890)
 val wc = data.flatMap(_.split(" ")).map (x => (x,1)).reduceByKey(_+_)
 wc.print()
 wc.saveAsTextFiles("hdfs://localhost:9000/user/streamingexa/ex")
 ssc.start()


// start netcat and type something there
hadoop@hadoop:/$ nc -lk 7890
i love all beautiful things
god i love all beautiful
god i love
god i



 // result is printed on console

-------------------------------------------                                   
Time: 1549431720000 ms
-------------------------------------------
(god,3)
(i,4)
(all,2)
(beautiful,2)
(things,1)
(love,3)

-------------------------------------------

 // result is written in hdfs
hadoop@hadoop:/$ hdfs dfs -ls hdfs://localhost:9000/user/streamingexa/
Found 1 items
drwxr-xr-x   - hadoop supergroup          0 2019-02-06 11:12 hdfs://localhost:9000/user/streamingexa/ex-1549431720000
hadoop@hadoop:/$ hdfs dfs -ls hdfs://localhost:9000/user/streamingexa/ex-1549431720000
Found 5 items
-rw-r--r--   3 hadoop supergroup          0 2019-02-06 11:12 hdfs://localhost:9000/user/streamingexa/ex-1549431720000/_SUCCESS
-rw-r--r--   3 hadoop supergroup          8 2019-02-06 11:12 hdfs://localhost:9000/user/streamingexa/ex-1549431720000/part-00000
-rw-r--r--   3 hadoop supergroup         39 2019-02-06 11:12 hdfs://localhost:9000/user/streamingexa/ex-1549431720000/part-00001
-rw-r--r--   3 hadoop supergroup          9 2019-02-06 11:12 hdfs://localhost:9000/user/streamingexa/ex-1549431720000/part-00002
-rw-r--r--   3 hadoop supergroup          0 2019-02-06 11:12 hdfs://localhost:9000/user/streamingexa/ex-1549431720000/part-00003
hadoop@hadoop:/$ hdfs dfs -cat hdfs://localhost:9000/user/streamingexa/ex-1549431720000/part-00001
(i,4)
(all,2)
(beautiful,2)
(things,1)

One more approach without stopping SparkContext:
---------------------------------------------------------------
hadoop@hadoop:~$ spark-shell --master local[2]

import org.apache.spark.streaming._
val ssc = new StreamingContext(sc,Seconds(15))
val d1 = ssc.socketTextStream("localhost",1234)
val d2 = d1.flatMap(x => x.split(" ")).map(x => (x,1)).reduceByKey( (x,y) => (x+y))

d2.print()
sc.setLogLevel("INFO")
ssc.start()


hadoop@hadoop:~$ nc -lk 1234
hadoop is batch processing


Time: 1549458165000 ms
-------------------------------------------
(is,1)
(batch,1)
(hadoop,1)
(processing,1)


import org.apache.spark.sql.SQLContext
import org.apache.spark.streaming.{Seconds,StreamingContext}
import org.apache.spark.{SparkConf,SparkContext}
import org.apache.spark.sql.functions._

object Streaming1{
def main(args:Array[String]):Unit = {

// Create a configuration object
val conf = new SparkConf()
conf.set("spark.master","local[2]")
conf.set("spark.app.name","streamingApp1")
conf.set("spark.streaming.blockInterval","1000ms")

//creation of spark context object
val sc = new SparkContext(conf)

//creation of sqlContext
val sqlContext = new SQLContext(sc)
import sqlContext.implicits._

// Creation of Streaming Context
val ssc = new StreamingContext(sc,Seconds(2))

//Receiver Port
val d1 = ssc.socketTextStream("localhost",3456)

// DStream (sequence of RDDs) into Dataframe
d1.foreachRDD { x =>
val ds1 = x.toDS()
val ds2 = ds1.flatMap(x => x.split(" "))
val ds3 = ds2.map(x => (x,1))
ds3.groupBy("_1").agg(count("_2")).show
}
ssc.start()
ssc.awaitTermination()

}
}


// start netcat and open port 3456
hadoop@hadoop:~/Desktop/vow$ nc -lk 3456
god hath no better prize
love is love
love is life
life is love

//start spark shell
$ spark-shell --master local[2]

//stop existing SparkContext
scala> sc.stop

//load spark (scala) file
scala> :load streamingDF.sc

// call the main method
scala> Streaming1.main(null)

// result

+------+---------+

|    _1|count(_2)|

+------+---------+

|  love|        4|

|  life|        2|

|    is|        3|

|  hath|        1|

|   god|        1|

|better|        1|

|    no|        1|

| prize|        1|

+------+---------+