long-ride-alerts/src/main/scala/org/apache/flink/training/exercises/longrides/scala/LongRidesExercise.scala

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 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
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 *     http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.flink.training.exercises.longrides.scala

import org.apache.flink.configuration.Configuration
import org.apache.flink.streaming.api.TimeCharacteristic
import org.apache.flink.streaming.api.functions.KeyedProcessFunction
import org.apache.flink.streaming.api.scala.{StreamExecutionEnvironment, _}
import org.apache.flink.training.exercises.common.datatypes.TaxiRide
import org.apache.flink.training.exercises.common.sources.TaxiRideGenerator
import org.apache.flink.training.exercises.common.utils.ExerciseBase._
import org.apache.flink.training.exercises.common.utils.{ExerciseBase, MissingSolutionException}
import org.apache.flink.util.Collector

/**
  * The "Long Ride Alerts" exercise of the Flink training in the docs.
  *
  * The goal for this exercise is to emit START events for taxi rides that have not been matched
  * by an END event during the first 2 hours of the ride.
  *
  */
object LongRidesExercise {

  def main(args: Array[String]) {

    // set up the execution environment
    val env = StreamExecutionEnvironment.getExecutionEnvironment
    env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime)
    env.setParallelism(ExerciseBase.parallelism)

    val rides = env.addSource(rideSourceOrTest(new TaxiRideGenerator()))

    val longRides = rides
      .keyBy(_.rideId)
      .process(new ImplementMeFunction())

    printOrTest(longRides)

    env.execute("Long Taxi Rides")
  }

  class ImplementMeFunction extends KeyedProcessFunction[Long, TaxiRide, TaxiRide] {

    override def open(parameters: Configuration): Unit = {
      throw new MissingSolutionException()
    }

    override def processElement(ride: TaxiRide,
                                context: KeyedProcessFunction[Long, TaxiRide, TaxiRide]#Context,
                                out: Collector[TaxiRide]): Unit = {
    }

    override def onTimer(timestamp: Long,
                         ctx: KeyedProcessFunction[Long, TaxiRide, TaxiRide]#OnTimerContext,
                         out: Collector[TaxiRide]): Unit = {
    }

  }

}