Flink window Function - FoldFunction
package window
import org.apache.flink.api.common.functions.{AggregateFunction, FoldFunction}
import org.apache.flink.api.scala._
import org.apache.flink.streaming.api.functions.source.SourceFunction
import org.apache.flink.streaming.api.scala.{StreamExecutionEnvironment, WindowedStream}
import org.apache.flink.streaming.api.windowing.time.Time
import org.apache.flink.streaming.api.windowing.windows.TimeWindow
/**
* @author: create by maoxiangyi
* @version: v1.0
* @description: window
* @date:2019 /6/4
*/
object FoldWordCount {
def main(args: Array[String]): Unit = {
//设置环境
val env: StreamExecutionEnvironment = StreamExecutionEnvironment.createLocalEnvironment()
//设置数据源
val window: WindowedStream[(String, Int), String, TimeWindow] = 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))
window.fold(("", 0), new FoldFunction[(String, Int), (String, Int)] {
override def fold(accumulator: (String, Int), value: (String, Int)): (String, Int) = {
(value._1, value._2 + accumulator._2)
}
}).print()
env.execute("word count")
}
}
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