Flink的ProcessFunction的状态和定时器

 DataStream.process(processFucntion)

KeyedDataStream .process(keyedProcessFunction)

windowStream .process(processWindowFunction)

connectedStream.process(CoProcessFunction)

windowAllSteam.process(processAllWindowFunction)

processFunction都继承了RichFunction

package flinkSourse

import org.apache.flink.api.common.state.{ValueState, ValueStateDescriptor}
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.functions.timestamps.BoundedOutOfOrdernessTimestampExtractor
import org.apache.flink.streaming.api.scala._
import org.apache.flink.streaming.api.windowing.time.Time
import org.apache.flink.util.Collector

object FlinkProcessFunction {
  def main(args: Array[String]): Unit = {
    val executionEnvironment: StreamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment
    executionEnvironment.setParallelism(1)
    //    executionEnvironment.setStreamTimeCharacteristic(TimeCharacteristic.EventTime) //watermark周期性生成，默认是200ms

    val stream2: DataStream[String] = executionEnvironment.socketTextStream("127.0.0.1", 1111)
    val transforStream: DataStream[SensorReading] = stream2.map(data => {
      val tmpList: Array[String] = data.split(",")
      SensorReading(tmpList(0), tmpList(1).toLong * 1000, tmpList(2).toDouble)
    })

    //如果10s内的温度是连续上升的，输出报警信息
    //如果当前温度是上升的，就加一个10s的定时器，如果10s连续上升则报警
    transforStream.keyBy(_.id).process(new TemperatureIncreWarning(20000)).print("warningStream")


    executionEnvironment.execute("transform")

  }
}


class TemperatureIncreWarning(timeDuration: Int) extends KeyedProcessFunction[String, SensorReading, String] {
  //保存一个状态进行温度数据比较，保存一个状态存储最初时间戳的状态
  var lastTempraturValueState: ValueState[Double] = _
  var initTimeStampValueState: ValueState[Long] = _


  override def open(parameters: Configuration): Unit = {
    lastTempraturValueState = getRuntimeContext.getState(new ValueStateDescriptor[Double]("last-tempeatrue", classOf[Double])) //默认值为0.0
    initTimeStampValueState = getRuntimeContext.getState(new ValueStateDescriptor[Long]("init-TimeStamp", classOf[Long])) //默认值为0
  }

  //每条数据都要走这个方法
  override def processElement(i: SensorReading, context: KeyedProcessFunction[String, SensorReading, String]#Context, collector: Collector[String]): Unit = {
    val lastTemp = lastTempraturValueState.value()
    //没有定时器时initTime就是0，保存第一次温度上升的时间戳，方便后续删除，当定时器消失后进行clear，表明当时没有定时器了，整个过程只有一个定时器,
    val initTime = initTimeStampValueState.value()
    println("lastTemp" + lastTemp)
    //当前温度和上次温度进行比较
    if (i.temperature > lastTemp && initTime == 0) {
      //  如果当前温度上升，并且没有定时器，则注册当前数据时间戳10s后的定时器,之前在这一步遇到了问题，记住要使用timerService().currentProcessingTime()
      val currentTimeStamp = context.timerService().currentProcessingTime() + timeDuration
      context.timerService().registerProcessingTimeTimer(currentTimeStamp)
      println("注册定时器" + currentTimeStamp)
      initTimeStampValueState.update(currentTimeStamp)
    } else if (i.temperature > lastTemp && initTime != 0) {
      //更新最新温度值
      println("温度值" + i.temperature + "比上次温度值" + lastTemp + "高，更新最新温度")
    } else if (i.temperature < lastTemp) {
      //如果当前温度下降，则删除上次保存的初始状态的定时器
      println("温度值" + i.temperature + "比上次温度值" + lastTemp + "低，但依然更新最新温度")
      context.timerService().deleteProcessingTimeTimer(initTime)
      println("销毁定时器" + initTime)

      //当定时器消失后进行clear，表明当时没有定时器了，整个过程只有一个定时器
      initTimeStampValueState.clear()
    }
    //      温度上升还是下降我们都保存上次的温度值，不进行清空而是进行赋值
    lastTempraturValueState.update(i.temperature)

  }

  //定时器10s后触发，才执行这个方法
  override def onTimer(timestamp: Long, ctx: KeyedProcessFunction[String, SensorReading, String]#OnTimerContext, out: Collector[String]): Unit = {
    //如果定时器没有被删除，那么就说明当前温度是连续10s上升的，否则之前就被删除了.定时器自己触发就不需要再删除了
    out.collect("传感器" + ctx.getCurrentKey + "的定时器" + timestamp + "连续" + timeDuration + "秒上升")
    //当定时器消失后进行clear，表明当时没有定时器了，整个过程只有一个定时器
    initTimeStampValueState.clear()

  }
}