Flink输出到Redis

Posted 2021-03-17 大牛和小白

   1.代码

import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
import org.apache.flink.streaming.connectors.redis.RedisSink
import org.apache.flink.streaming.connectors.redis.common.config.FlinkJedisPoolConfig
import org.apache.flink.streaming.connectors.redis.common.mapper.{RedisCommand, RedisCommandDescription, RedisMapper}

//温度传感器读取样例类
case class SensorReading(id: String, timestamp: Long, temperature: Double)

object RedisSinkTest {
  def main(args: Array[String]): Unit = {
    val env = StreamExecutionEnvironment.getExecutionEnvironment
    env.setParallelism(1)

    //source
    val inputStream  = env.readTextFile("sensor1.txt")

    //transform
    import org.apache.flink.api.scala._
    val dataStream = inputStream.map(x => {
      val arr = x.split(",")
      SensorReading(arr(0).trim, arr(1).trim.toLong, arr(2).trim.toDouble)
    })

    //sink
    val conf = new FlinkJedisPoolConfig.Builder().setHost("localhost").setPort(6379).build()

    dataStream.addSink(new RedisSink[SensorReading](conf, new MyRedisMapper))

    env.execute("redis sink test")
  }
}

//定义一个redis的mapper类,用于定义保存到redis时调用的命令
class MyRedisMapper extends RedisMapper[SensorReading] {
  override def getCommandDescription: RedisCommandDescription = {
    //把传感器id和温度值保存成哈希表: HSET key field value
    new RedisCommandDescription(RedisCommand.HSET, "sensor_temperature")
  }

  //相当于是field
  override def getKeyFromData(data: SensorReading): String = {
    data.id
  }

  override def getValueFromData(data: SensorReading): String = {
    data.temperature.toString
  }

}

2.结果
 

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