Redis-backed sessions

The spring-session-data-redis module stores sessions in Redis through a reactive Redis connection, so sessions survive application restarts and are shared between all instances that point at the same Redis.

Step 1: add the dependencies

<dependency>
    <groupId>org.springframework.session</groupId>
    <artifactId>spring-session-data-redis</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-redis</artifactId>
</dependency>
<dependency>
    <groupId>io.lettuce</groupId>
    <artifactId>lettuce-core</artifactId>
</dependency>

Lettuce is the required driver for reactive Redis support (see Spring Data Redis).

Step 2: configure the Redis connection factory

@Configuration
public class RedisConfig {

    @Bean
    public LettuceConnectionFactory redisConnectionFactory() {
        return new LettuceConnectionFactory();
    }
}

The default LettuceConnectionFactory connects to localhost:6379. To start a Redis server for local development, use the docker-compose.yml in the repository root:

docker-compose up redis

Step 3: enable Redis web session

@Configuration
@EnableRedisWebSession
public class SessionConfig {
}

@EnableRedisWebSession registers a reactive session repository backed by Redis automatically — no explicit ReactiveSessionRepository bean is needed. The controller and template code is identical to the in-memory example.

Verify

Start the application and submit the attribute form at http://localhost:8080. Then inspect Redis directly:

redis-cli keys "spring:session*"

You will find the session keyed under the spring:session prefix, storing the attributes and metadata.

You can explore the complete codes in spring-reactive-sample/session-data-redis.