Flink Redis Sink 基本用法

简介

flink提供了专门操作redis的Redis Sink

依赖

 <dependency>
    <groupId>org.apache.bahirgroupId>
    <artifactId>flink-connector-redis_2.11artifactId>
    <version>1.0version>
dependency>

类

Redis Sink 提供用于向Redis发送数据的接口的类。接收器可以使用三种不同的方法与不同类型的Redis环境进行通信：

类	场景	备注
FlinkJedisPoolConfig	单Redis服务器	适用于本地、测试场景
FlinkJedisClusterConfig	Redis集群
FlinkJedisSentinelConfig	Redis哨兵

使用

Redis Sink 核心类是 RedisMappe 是一个接口，使用时我们要编写自己的redis操作类实现这个接口中的三个方法

RedisMapper

public interface RedisMapper<T> extends Function, Serializable {

    /**
     * 设置使用的redis数据结构类型，和key的名词
     * 通过RedisCommand设置数据结构类型
     * Returns descriptor which defines data type.
     *
     * @return data type descriptor
     */
    RedisCommandDescription getCommandDescription();

    /**
     * 设置value中的键值对 key的值
     * Extracts key from data.
     *
     * @param data source data
     * @return key
     */
    String getKeyFromData(T data);

    /**
     * 设置value中的键值对 value的值
     * Extracts value from data.
     *
     * @param data source data
     * @return value
     */
    String getValueFromData(T data);
}

RedisCommand

使用RedisCommand设置数据结构类型时和redis结构对应关系。

Data Type	Redis Command [Sink]
HASH	HSET
LIST	RPUSH, LPUSH
SET	SADD
PUBSUB	PUBLISH
STRING	SET
HYPER_LOG_LOG	PFADD
SORTED_SET	ZADD
SORTED_SET	ZREM

Demo

package com.yljphp.demo.sink

import org.apache.flink.streaming.api.scala._
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}
import org.apache.flink.util.StringUtils

object RedisBasicApp extends App {

  val env = StreamExecutionEnvironment.getExecutionEnvironment

  env.setParallelism(1)

  val text: DataStream[String] = env.socketTextStream("localhost", 9000)

  val data: DataStream[(String, String)] = text.filter(!StringUtils.isNullOrWhitespaceOnly(_))
    .flatMap(_.split(","))
    .map(("ylj_test_1", _))
    .map(x=>{
      println(x)
      x
    })


  val config: FlinkJedisPoolConfig = new FlinkJedisPoolConfig.Builder()
    .setHost("localhost")
    .setPort(6379)
    .build()


  val redisSink = new RedisSink[(String,String)](config,new MyRedisMapper)

  data.addSink(redisSink)

  env.execute("sink_demo")
}

class MyRedisMapper extends RedisMapper[(String, String)] {
  override def getCommandDescription: RedisCommandDescription = {
    new RedisCommandDescription(RedisCommand.SADD, "ylj_test_2")
  }

  override def getKeyFromData(data: (String, String)): String = data._1

  override def getValueFromData(data: (String, String)): String = data._2
}

参考

Flink Redis Connector