Word count program using Dataframe and DataSet

Word count program using Dataframe and DataSet:
-------------------------------------
scala> val df = spark.read.format("text").load("e://vow//sample.txt")
df2: org.apache.spark.sql.DataFrame = [value: string]

scala> df.printSchema
root
 |-- value: string (nullable = true)


scala> df.show
+--------------------+
|               value|
+--------------------+
|spark is  bigdata...|
|hadoop is bigdata...|
|spark and hadoop ...|
+--------------------+

scala> val ds = df.as[String]
ds: org.apache.spark.sql.Dataset[String] = [value: string]

scala> ds.show
+--------------------+
|               value|
+--------------------+
|spark is  bigdata...|
|hadoop is bigdata...|
|spark and hadoop ...|
+--------------------+

scala> val ds1 = ds.map(x => x.split(" "))
ds1: org.apache.spark.sql.Dataset[Array[String]] = [value: array<string>]

scala> ds1.show
+--------------------+
|               value|
+--------------------+
|[spark, is, , big...|
|[hadoop, is, bigd...|
|[spark, and, hado...|
+--------------------+

scala> val ds2 = ds.flatMap(x => x.split(" "))
ds2: org.apache.spark.sql.Dataset[String] = [value: string]

scala> ds2.show
+------------+
|       value|
+------------+
|       spark|
|          is|
|            |
|     bigdata|
|  technology|
|      hadoop|
|          is|
|     bigdata|
|  technology|
|       spark|
|         and|
|      hadoop|
|         are|
|     bigdata|
|technologies|
+------------+

scala> val ds3 = ds2.map(x => (x,1))
ds3: org.apache.spark.sql.Dataset[(String, Int)] = [_1: string, _2: int]

scala> ds3.show
+------------+---+
|          _1| _2|
+------------+---+
|       spark|  1|
|          is|  1|
|            |  1|
|     bigdata|  1|
|  technology|  1|
|      hadoop|  1|
|          is|  1|
|     bigdata|  1|
|  technology|  1|
|       spark|  1|
|         and|  1|
|      hadoop|  1|
|         are|  1|
|     bigdata|  1|
|technologies|  1|
+------------+---+

scala> df.groupBy("_1").agg(count("_2")).show
+------------+---------+
|          _1|count(_2)|
+------------+---------+
|  technology|        2|
|          is|        2|
|       spark|        2|
|         and|        1|
|         are|        1|
|technologies|        1|
|     bigdata|        3|
|            |        1|
|      hadoop|        2|
+------------+---------+