令牌桶限流

引入redis的maven依赖

<dependency>
   <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
    <version>2.6.6</version>
</dependency>

增加config配置

@Configuration
public class RedisConfig {

  @Bean
  public RedisTemplate<String,Object> redisTemplate(LettuceConnectionFactory lettuceConnectionFactory) {
    RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
    redisTemplate.setConnectionFactory(lettuceConnectionFactory);
    redisTemplate.setKeySerializer(RedisSerializer.string());
    redisTemplate.setValueSerializer(RedisSerializer.string());
    return redisTemplate;
  }
}

设置定时任务以固定时间增加令牌桶数量，decr接口是处理业务消费令牌的

@Slf4j
@EnableScheduling
@RestController
public class RedisController {

    @Autowired
    private RedisTemplate<String,Object> redisTemplate;

    @GetMapping("/decr")
    public void decr(){
        Object list = redisTemplate.opsForList().leftPop("list");
        if(list == null){
            log.info("系统繁忙，请稍后重试！");
            return;
        }
        log.info("可以进入处理业务 {}",list);
    }

    @Scheduled(cron = "1/5 * * * * ?")
    public void incr(){
        Long list = redisTemplate.opsForList().size("list");
        log.info("令牌桶数量为 ：{}",list);
        if (list == null || list < 20) {
            for (int i = 0; i < 10; i++) {
                redisTemplate.opsForList().leftPush("list", UUID.randomUUID().toString());
            }
        }
    }
}