Flink cep notFllowedBy 用法案例

notFllowedBy 意思是只保留第一个条件最后的一条数据跟第二个条件去匹配

notNext() notFollowedBy()

后面的模式不命中（严格/非严格）

 

下图代码说明的就是，匹配最后一个 name = '2',，接下来遇到 '0'  就是匹配结果，所有会有2个结果

(Event(A,a3,2) ,Event(A,a6,0))
(-Event(A,a8,2),Event(A,a10,0))

package com.coder.flink.restart

import org.apache.flink.cep.scala.{CEP, PatternStream}
import org.apache.flink.cep.scala.pattern.Pattern
import org.apache.flink.streaming.api.scala.{DataStream, StreamExecutionEnvironment}
import org.apache.flink.streaming.api.scala._
import scala.collection.Map

object demo1 {
  case class Event(types: String, temp: String, name: String)

  def main(args: Array[String]): Unit = {

    val env = StreamExecutionEnvironment.getExecutionEnvironment
    val data: DataStream[Event] = env.fromElements(

      Event("A", "a1", "2"),
      Event("A", "a2", "2"),
      Event("A", "a3", "2"),
      Event("A", "a4", "1"),
      Event("A", "a5", "1"),
      Event("A", "a6", "0"),
      Event("A", "a7", "3"),
      Event("A", "a8", "2"),
      Event("A", "a9", "1"),
      Event("A", "a10", "0")
    )

    //定义Pattern接口
    val pattern = Pattern.begin[Event]("start") //指定名称
      .where(_.name.equals("2"))
      .notFollowedBy("middle") //接下来的名称
      .subtype(classOf[Event]) //可以将Event事件转换TempEvent事件
      .where(_.name.endsWith("2"))
      .followedBy("last").where(_.name.endsWith("0"))

    val patternStream: PatternStream[Event] = CEP.pattern(data, pattern)

    //获取触发事件
    val reslut: DataStream[List[Event]] = patternStream.select((pat: Map[String, Iterable[Event]]) => {
      val rs: List[Event] = pat.get("last").get.toList
      val rs2: List[Event] = pat.get("start").get.toList
      val aa: Event = rs(0)
      val aa2: Event = rs2(0)
      println(aa +"----"+aa2)
      rs
    })



    reslut.print()
    //    data.print()
    env.execute()
  }
}

 

输出结果为：

Event(A,a6,0)----Event(A,a3,2)
Event(A,a10,0)----Event(A,a8,2)
2> List(Event(A,a10,0))
1> List(Event(A,a6,0))