Flink中Table表和DataStream流的互相转换

sensor.txt

sensor_1,1547718199,35.8
sensor_6,1547718201,15.4
sensor_7,1547718202,6.7
sensor_10,1547718205,38.1
sensor_1,1547718207,37.2
sensor_1,1547718212,33.5
sensor_1,1547718215,38.1

转换代码

import org.apache.flink.streaming.api.scala._
import org.apache.flink.table.api.scala._
import org.apache.flink.table.api.{DataTypes, Table}
import org.apache.flink.table.descriptors.{Csv, FileSystem, Schema}


//  表和流互相转换
object OutputTableTest2 {
  def main(args: Array[String]): Unit = {
    val env = StreamExecutionEnvironment.getExecutionEnvironment
    env.setParallelism(1)

    // 读取数据创建DataStream
    val inputStream: DataStream[String] = env.
      readTextFile("D:\\20-Flink\\FlinkTutorial\\src\\main\\resources\\sensor.txt")

    // 流
    val dataStream: DataStream[SensorReading] = inputStream
      .map(data => {
        val dataArray = data.split(",")
        SensorReading(dataArray(0), dataArray(1).toLong, dataArray(2).toDouble)
      })

    val tableEnv: StreamTableEnvironment = StreamTableEnvironment.create(env)

      // 将流转成了表
    val sensorTable: Table = tableEnv.fromDataStream(dataStream, 'id, 'temperature as 'temp, 'timestamp as 'ts)

      
    // 将表转成了流
    val value: DataStream[(String, Double, Long)] = sensorTable.toAppendStream[(String, Double, Long)]
   // 输出表
    value.print()

    env.execute("output table test")
  }
}

输出结果

可以发现输入的内容和输出的内容是一模一样的.

(sensor_1,35.8,1547718199)
(sensor_6,15.4,1547718201)
(sensor_7,6.7,1547718202)
(sensor_10,38.1,1547718205)
(sensor_1,37.2,1547718207)
(sensor_1,33.5,1547718212)
(sensor_1,38.1,1547718215)