Spring Data Redis

  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
  

  spring:
  data:
    redis:
      host: localhost
      port: 6379
      password: ${REDIS_PASSWORD:}
      timeout: 2000ms
      lettuce:
        pool:
          max-active: 8
          max-idle: 8
  

  @Configuration
public class RedisConfig {
    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(factory);
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
        return template;
    }
}
  

  @Service
public class CacheService {
    private final RedisTemplate<String, Object> redisTemplate;

    public void set(String key, Object value, Duration ttl) {
        redisTemplate.opsForValue().set(key, value, ttl);
    }

    public <T> T get(String key, Class<T> type) {
        Object value = redisTemplate.opsForValue().get(key);
        return type.cast(value);
    }

    public void delete(String key) {
        redisTemplate.delete(key);
    }
}
  

  // List
redisTemplate.opsForList().rightPush("queue:orders", orderId);
String id = (String) redisTemplate.opsForList().leftPop("queue:orders");

// Set
redisTemplate.opsForSet().add("online:users", userId);
boolean online = redisTemplate.opsForSet().isMember("online:users", userId);

// Hash
redisTemplate.opsForHash().put("user:1", "name", "Alice");
String name = (String) redisTemplate.opsForHash().get("user:1", "name");

// Sorted Set (leaderboard)
redisTemplate.opsForZSet().add("leaderboard", userId, score);
Set<Object> top10 = redisTemplate.opsForZSet().reverseRange("leaderboard", 0, 9);
  

  @EnableCaching
@Configuration
public class CacheConfig {
    @Bean
    public RedisCacheManager cacheManager(RedisConnectionFactory factory) {
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
            .entryTtl(Duration.ofMinutes(10))
            .serializeValuesWith(
                RedisSerializationContext.SerializationPair.fromSerializer(
                    new GenericJackson2JsonRedisSerializer()));
        return RedisCacheManager.builder(factory)
            .cacheDefaults(config)
            .build();
    }
}

@Service
public class UserService {
    @Cacheable(value = "users", key = "#id")
    public User findById(Long id) { return userRepository.findById(id).orElseThrow(); }

    @CacheEvict(value = "users", key = "#user.id")
    public User update(User user) { return userRepository.save(user); }
}
  

  @RedisHash("session")
public class UserSession {
    @Id
    private String sessionId;
    private Long userId;
    @TimeToLive
    private Long ttl = 3600L;
}

public interface SessionRepository extends CrudRepository<UserSession, String> {
    List<UserSession> findByUserId(Long userId);
}