Redis increment 函数处理并发序列号案例

spring:
  cache:
    type: GENERIC
  redis:
    host: ${sy.redis.ip}
    password:
    port: ${sy.redis.port}
    database: ${sy.redis.database}

import org.springframework.cache.CacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import java.time.Duration;
@Configuration
public class CacheConfig {
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {
        RedisCacheConfiguration cacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofMinutes(10)) // 设置缓存过期时间
                .disableCachingNullValues()
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new GenericJackson2JsonRedisSerializer()));
        return RedisCacheManager.builder(redisConnectionFactory)
                .cacheDefaults(cacheConfiguration)
                .build();
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
@Service
public class SequenceService {
    @Autowired
    private StringRedisTemplate redisTemplate;
    public long getDailySequence() {
        String dateStr = DateUtils.format(new Date(), "yyyy-MM-dd");
        String key = "dailySequence_" + dateStr;
        // 执行 increment 操作
        Long applicantNumber = redisTemplate.opsForValue().increment(key);
        // 设置过期时间为2天，不设置默认永久
        redisTemplate.expire(key, 2, TimeUnit.DAYS);
        //redisTemplate.expire(key) // 查询key的过期时间。
        //-1: 表示键存在但没有设置过期时间。
        //-2: 表示键不存在。
        //返回秒：如上面返回值是 172780，这意味着该键将在大约 172780 秒（约 48 小时）后过期。
        return applicantNumber;
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class SequenceController {
    @Autowired
    private SequenceService sequenceService;
    @GetMapping("/daily-sequence")
    public String getDailySequence() {
        long sequence = sequenceService.getDailySequence();
        return "Daily sequence: " + sequence;
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
@SpringBootApplication
@EnableCaching
public class RedisIncrApplication {
    public static void main(String[] args) {
        SpringApplication.run(RedisIncrApplication.class, args);
    }
}