SparkStreaming WordCount入门案例

package com.lqs.sparkstreaming

import org.apache.spark.SparkConf
import org.apache.spark.streaming.dstream.{DStream, ReceiverInputDStream}
import org.apache.spark.streaming.{Seconds, StreamingContext}

/**
 * @Author lqs
 * @Date 2022年02月16日 18:40:47
 * @Version 1.0.0
 * @ClassName WordCount
 * @Describe WordCount案例实操
 *
 *           需求：
 *           使用netcat工具向8888端口不断的发送数据，通过SparkStreaming读取端口数据并统计不同单词出现的次数。
 */
object Qs01_WordCount {
  def main(args: Array[String]): Unit = {
    //TODO 1、初始化SparkStreaming配置信息
    val conf: SparkConf = new SparkConf().setMaster("local[*]").setAppName("SparkStreamin")

    //TODO 2、初始化SparkStreamingContext
    //Seconds(3):设置微批次流的间隔时间为3sec
    val streamingContext = new StreamingContext(conf, Seconds(3))

    //通过端口创建DStream，读取进来的数据为一行行
    val lineDStream: ReceiverInputDStream[String] = streamingContext.socketTextStream("bdc112", 8888)

    //将数据按行进行切分成一个个的单词
    val wordDStream: DStream[String] = lineDStream.flatMap(_.split(" "))

    //将单词映射成元组(word,1)
    val wordToOneDStream: DStream[(String, Int)] = wordDStream.map((_, 1))

    //将相同的单词数做统计
    val wordToSumDStream: DStream[(String, Int)] = wordToOneDStream.reduceByKey(_ + _)

    //打印到控制台
    wordToSumDStream.print()

    //TODO 3、启动SparkStreamingContext
    streamingContext.start()

    //TODO 4、将主线程阻塞，主线程不退出
    streamingContext.awaitTermination()
  }
}

启动程序并通过netcat发送数据

[lqs@bdc112 datas]$ nc -lk 8888
lqs lqs Hello Word h^HH^H^H^H
lqs Hello Woed
lqs

运行结果：

-------------------------------------------
Time: 1645009179000 ms
-------------------------------------------

-------------------------------------------
Time: 1645009182000 ms
-------------------------------------------

-------------------------------------------
Time: 1645009185000 ms
-------------------------------------------
,1)
(Hello,1)
(Word,1)
(lqs,2)

-------------------------------------------
Time: 1645009188000 ms
-------------------------------------------

-------------------------------------------
Time: 1645009203000 ms
-------------------------------------------
(Hello,1)
(Woed,1)
(lqs,1)

-------------------------------------------
Time: 1645009206000 ms
-------------------------------------------
(lqs,1)