Flink入门及实战（8）- DataStream 的 sink

1 DataStream 的 sink

1.1 向 redis 写数据

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

• 启动 redis
  
  
  

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package com.tzb.demo.streaming.sink;

import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.connectors.redis.RedisSink;
import org.apache.flink.streaming.connectors.redis.common.config.FlinkJedisClusterConfig;
import org.apache.flink.streaming.connectors.redis.common.config.FlinkJedisPoolConfig;
import org.apache.flink.streaming.connectors.redis.common.mapper.RedisCommand;
import org.apache.flink.streaming.connectors.redis.common.mapper.RedisCommandDescription;
import org.apache.flink.streaming.connectors.redis.common.mapper.RedisMapper;

/**
 * 接收 socket 数据，保存到 redis(一般是 list 或者 hashmap)
 *
 */
public class StreamingDemoToRedis {

    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        DataStreamSource<String> text = env.socketTextStream("master", 9000, "\n");

        // 对数据组装
        SingleOutputStreamOperator<Tuple2<String, String>> l_wordsData = text.map(new MapFunction<String, Tuple2<String, String>>() {

            @Override
            public Tuple2<String, String> map(String value) {
                return new Tuple2<>("l_words", value);
            }
        });

        FlinkJedisPoolConfig conf = new FlinkJedisPoolConfig.Builder().setHost("master").setPassword("123").setPort(6379).build();

        RedisSink<Tuple2<String, String>> redisSink = new RedisSink<>(conf, new MyRedisMapper());

        l_wordsData.addSink(redisSink);

        env.execute("StreamingDemoToRedis");

    }

    public static class MyRedisMapper implements RedisMapper<Tuple2<String,String>>{

        @Override
        public RedisCommandDescription getCommandDescription() {
            return new RedisCommandDescription(RedisCommand.LPUSH);
        }

        // 从获取的数据中获取需要操作的 key
        @Override
        public String getKeyFromData(Tuple2<String, String> stringStringTuple2) {
            return stringStringTuple2.f0;
        }

        @Override
        public String getValueFromData(Tuple2<String, String> stringStringTuple2) {
            return stringStringTuple2.f1;
        }
    }

}

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