[嵌入式]创建flink的MqttSource (scala版本)

一.编写 MqttClient类

class MqttClient {

  var url:String="tcp://192.168.174.206:1883"
  var flag:Boolean=true
  private val topicArr: Array[Topic] = List(new Topic("topic_test",QoS.AT_LEAST_ONCE),new Topic("topic_test",QoS.AT_MOST_ONCE),new Topic("topic_test",QoS.EXACTLY_ONCE)).toArray

  //开始连接
  def  start():FutureConnection={
     val mqtt = new MQTT()

    mqtt.setHost(url) //设置连接地址
    mqtt.setCleanSession(true)//是否清空会话信息
    mqtt.setReconnectAttemptsMax(10) //设置最大的重新连接次数
    mqtt.setReconnectDelay(10) //设置重新连接的时长
    mqtt.setKeepAlive(30) //设置心跳时间
    mqtt.setSendBufferSize(64) //设置缓冲区的大小
    mqtt.setClientId("clientid_0001")

    val connection: FutureConnection = mqtt.futureConnection()
    connection.connect()
    connection.subscribe(topicArr)

    return connection

  }

}

?2.编辑MqttSource

object MqttSource extends RichSourceFunction[String] {

   var flag:Boolean=true
  override def run(sourceContext: SourceFunction.SourceContext[String]): Unit = {
    val client = new MqttClient()
    val connection: FutureConnection = client.start()

    var msg:String=""

    while (true){
      val futureMessage: Future[Message] = connection.receive()
      val message: Message = futureMessage.await()
      msg = String.valueOf(message.getPayloadBuffer()).substring(6)
      sourceContext.collect(msg)
    }
  }
  override def cancel(): Unit = {
    flag=false
  }
}

?三,编辑flink主类?flinkMQtt

object flinkMQtt {
  def main(args: Array[String]): Unit = {
  //创建执行的环境
   val env: StreamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment
  //设置并行度
   env.setParallelism(1)
   val mqttDS: DataStreamSource[String] = env.addSource(MqttSource)
   mqttDS.print()
    
//执行job
env.execute()
  }
}

?存在一个问题:如果发送汉字字符串接,接收端收到一段数字?还没解决!!!知道的留下解决方式......