flink1.11新增水位線

object UpdateWindowResultWithLateEvent {
  def main(args: Array[String]): Unit = {
    val env = StreamExecutionEnvironment.getExecutionEnvironment
    env.setParallelism(1)
    env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime)

    val stream = env
      .socketTextStream(
 
"db2", 9999, '\n')
      .map(r => {
        val arr = r.split(" ")
        (arr(0), arr(1).toLong * 1000L)
      })
      .assignTimestampsAndWatermarks(
        WatermarkStrategy
          .forBoundedOutOfOrderness[(String, Long)](Duration.ofSeconds(5))
          .withTimestampAssigner(new SerializableTimestampAssigner[(String, Long)] {
            
 
override def extractTimestamp(element: (String, Long), recordTimestamp: Long): Long = element._2
          })
      )
      .keyBy(r => r._1)
      .timeWindow(Time.seconds(5))
      .allowedLateness(Time.seconds(5))
      .process(new CountWindow)

    stream.print()

    env.execute()
  }

  class
 
 CountWindow extends ProcessWindowFunction[(String, Long), String, String, TimeWindow] {
    override def process(key: String, context: Context, elements: Iterable[(String, Long)], out: Collector[String]): Unit = {
      // note that here is window state!!! only for current key and current window
      val isUpdate = context.windowState.getState(
        new ValueStateDescriptor[Boolean]("is-update", Types.of[Boolean])
      )

      if (!isUpdate.value()) {
        out.collect("first calculate window result!!!!")
        isUpdate.update(true)
      } else {
        out.collect("update window result!!!!")
      }
    }
  }
}