Spark WordCount 文档词频计数

Apache Spark is a fast and general-purpose cluster computing system.It provides high-level APIs in Java, Scala, Python and R, and an optimized engine that supports general execution graphs.
It also supports a rich set of higher-level tools including Spark SQL for SQL and structured data processing, MLlib for machine learning, GraphX for graph processing, and Spark Streaming.

package big.data.analyse.wordcount

import org.apache.spark.sql.SparkSession

/**
  * Created by zhen on 2019/3/9.
  */
object WordCount {
  def main(args: Array[String]) {
    val spark = SparkSession.builder().appName("WordCount")
      .master("local[2]")
      .getOrCreate()
    // 加载数据
    val textRDD = spark.sparkContext.textFile("src/big/data/analyse/wordcount/wordcount.txt")
    val result = textRDD.map(row => row.replace(",", ""))//去除文字中的,防止出现歧义
      .flatMap(row => row.split(" "))//把字符串转换为字符集合
      .map(row => (row, 1))//把每个字符串转换为map，便于计数
      .reduceByKey(_+_)//计数
    // 打印结果
    result.foreach(println)
  }
}

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