Flink之批处理WordCount

代码：
import org.apache.flink.api.scala._

object WordCount1 {
  def main(args: Array[String]): Unit ={
    //创建执行环境
    val env =  ExecutionEnvironment.getExecutionEnvironment
    //从文件中读取数据
    val inputPath = "hello.txt"
    val inputDS: DataSet[String] = env.readTextFile(inputPath)
    val wordCountDS: AggregateDataSet[(String, Int)] = inputDS.flatMap(_.split(" "))
      .map((_, 1))
      .groupBy(0) //按第一个字段分组
      .sum(1)     //对第二个字段求和

    wordCountDS.print()
  }
}

结果：