如何获取redis的spring boot中的用户数量

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

spring.redis.host=127.0.0.1
spring.redis.port=6379

@Configuration
public class RedisConfig {

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        RedisStandaloneConfiguration config = new RedisStandaloneConfiguration();
        config.setHostName("127.0.0.1");
        config.setPort(6379);
        return new LettuceConnectionFactory(config);
    }

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(connectionFactory);
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        return template;
    }
}

@Autowired
private RedisTemplate<String, Object> redisTemplate;

public long getUserCount() {
    Set<Object> users = redisTemplate.keys("user:*");
    return users.size();
}