直接上代码,例子来源于官网的wordcount例子
package Sparkstreaming
import org.apache.spark.SparkConf
import org.apache.spark.rdd.RDD
import org.apache.spark.sql.SparkSession
import org.apache.spark.storage.StorageLevel
import org.apache.spark.streaming.{Seconds, StreamingContext, Time}
object SQLtest {
def main(args: Array[String]): Unit = {
val conf = new SparkConf().setAppName("SQLtest").setMaster("local[2]")
val ssc = new StreamingContext(conf, Seconds(5))
val lines = ssc.socketTextStream("192.168.116.10", 9999)
val words = lines.flatMap(_.split(" "))
words.foreachRDD { (rdd: RDD[String], time: Time) =>
// Get the singleton instance of SparkSession
val spark = SparkSessionSingleton.getInstance(rdd.sparkContext.getConf)
import spark.implicits._
// Convert RDD[String] to RDD[case class] to DataFrame
val wordsDataFrame = rdd.map(w => Record(w)).toDF()
// Creates a temporary view using the DataFrame
wordsDataFrame.createOrReplaceTempView("words")
// Do word count on table using SQL and print it
val wordCountsDataFrame =
spark.sql("select word, count(*) as total from words group by word")
println(s"========= $time =========")
wordCountsDataFrame.show()
}
ssc.start()
ssc.awaitTermination()
}
case class Record(word: String)
/** Lazily instantiated singleton instance of SparkSession */
object SparkSessionSingleton {
@transient private var instance: SparkSession = _
def getInstance(sparkConf: SparkConf): SparkSession = {
if (instance == null) {
instance = SparkSession
.builder
.config(sparkConf)
.getOrCreate()
}
instance
}
}
}
测试
在Linux新建一个窗口,输入
可以发现IDEA控制台已经输出结果了