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  • Flink window Function

    package window

    import org.apache.flink.api.common.functions.AggregateFunction
    import org.apache.flink.streaming.api.functions.source.SourceFunction
    import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
    import org.apache.flink.streaming.api.windowing.time.Time
    import org.apache.flink.api.scala._

    /**
    * @author: create by maoxiangyi
    * @version: v1.0
    * @description: window
    * @date:2019 /6/4
    */
    object AggregateWordCount {
    def main(args: Array[String]): Unit = {
    //设置环境
    val env: StreamExecutionEnvironment = StreamExecutionEnvironment.createLocalEnvironment()
    //设置数据源
    env.addSource(new SourceFunction[String] {
    override def run(ctx: SourceFunction.SourceContext[String]): Unit = {
    while (true) {
    ctx.collect("hello hadoop hello storm hello spark")
    Thread.sleep(1000)
    }
    }

    override def cancel(): Unit = {}
    })
    //计算逻辑
    .flatMap(_.split(" "))
    .map((_, 1))
    .keyBy(_._1)
    .timeWindow(Time.seconds(10), Time.seconds(10))


    .aggregate(new AggregateFunction[(String, Int), (String, Int), (String, Int)] {
    override def createAccumulator(): (String, Int) = {
    ("", 0)
    }
    override def add(value: (String, Int), accumulator: (String, Int)): (String, Int) = {
    (value._1, accumulator._2 + value._2)
    }
    override def getResult(accumulator: (String, Int)): (String, Int) = accumulator

    override def merge(a: (String, Int), b: (String, Int)): (String, Int) = {
    (a._1, a._2 + b._2)
    }
    }).print().setParallelism(1)
    env.execute("word count")
    }
    }
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  • 原文地址:https://www.cnblogs.com/maoxiangyi/p/10977917.html
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