How can Flink read data from Redis?

One common way to read data in Flink is by connecting to Redis. Here are the general steps to read data from Redis using Flink:

1. Add the necessary dependencies: Include Redis-related dependencies in the pom.xml file of the Flink project, such as:

<dependency>
    <groupId>org.apache.flink</groupId>
    <artifactId>flink-connector-redis_2.11</artifactId>
    <version>${flink.version}</version>
</dependency>

1. Set up a Flink execution environment.

StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

1. Create a Redis connection configuration.

FlinkJedisPoolConfig jedisConfig = new FlinkJedisPoolConfig.Builder()
        .setHost("localhost")
        .setPort(6379)
        .build();

1. includeSource()

DataStream<String> dataStream = env.addSource(new RedisSource<>(jedisConfig, new MyRedisMapper()));

MyRedisMapper is a custom class that implements the RedisMapper interface, used to specify the data format in Redis and how data is mapped to Flink data streams.

1. RedisMapper is responsible for mapping data to and from a Redis database.

public class MyRedisMapper implements RedisMapper<String> {
    @Override
    public RedisCommandDescription getCommandDescription() {
        // 指定Redis命令，例如GET key
        return new RedisCommandDescription(RedisCommand.GET);
    }
    
    @Override
    public String getKeyFromData(String data) {
        // 从Redis中获取的数据中提取用于分区的键
        return data;
    }
    
    @Override
    public String getValueFromData(String data) {
        // 从Redis中获取的数据中提取值
        return data;
    }
}

1. could you please press the print button?

dataStream.print();

1. carry out

env.execute("Read from Redis");

In this way, Flink can read data from Redis and process it. Please make appropriate adjustments and extensions based on the actual situation.