主要包括有界流和*流

import java.util.Properties

import org.apache.flink.api.common.serialization.SimpleStringSchema
import org.apache.flink.streaming.api.functions.source.SourceFunction
import org.apache.flink.streaming.api.scala._
import org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumer010

import scala.collection.immutable
import scala.util.Random


case class SensorReading(id: String, timestamp: Long, temperature: Double)


object FlinkSourceExe {
  def main(args: Array[String]): Unit = {
    val executionEnvironment: StreamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment
    executionEnvironment.setParallelism(1)
    val dataList = List(SensorReading("sensor_1", 1558723892, 35.5), SensorReading("sensor_2", 1558709800, 35.6))
    //    1、有界流 env.fromCollectioin
    val stream1: DataStream[SensorReading] = executionEnvironment.fromCollection(dataList)
    //    2、有界流  env.readTextFile
    val stream2: DataStream[String] = executionEnvironment.readTextFile("src/main/resources/sensorReading.txt")

    //3、*流 kafka
    val properties = new Properties()
    properties.setProperty("bootstrap.servers", "localhost:9092")
    properties.setProperty("group.id", "consumer-group")
    //输出和kafka的并行度一致
    val stream3: DataStream[String] = executionEnvironment.addSource(new FlinkKafkaConsumer010[String]("topic1", new SimpleStringSchema(), properties))

    //4、*流 读取socket
    val stream4 = executionEnvironment.socketTextStream("127.0.0.1", 1111)


    //5、自定义Source
    val stream5 = executionEnvironment.addSource(new MySensorSource())

    stream5.print()


    executionEnvironment.execute()
  }
}

class MySensorSource() extends SourceFunction[SensorReading] {

  var running: Boolean = true

  override def run(sourceContext: SourceFunction.SourceContext[SensorReading]): Unit = {
    val random = Random
    val curtmp: immutable.IndexedSeq[(String, Double)] = 1.to(10).map(i => {
      ("sensor" + i, random.nextDouble() * 100)
    })

    while (running) {
      val readings: immutable.IndexedSeq[SensorReading] = curtmp.map(data => {
        SensorReading(data._1, System.currentTimeMillis(), data._2 + random.nextGaussian())
      })
      readings.foreach(data => {
        sourceContext.collect(data)
        Thread.sleep(2000)
      })

    }
  }


  override def cancel(): Unit = {
    running = false
  }
}