电商分布式订单号生成

import cn.hutool.core.collection.ConcurrentHashSet;
import com.baseus.mall.common.utils.OrderSnUtil;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.test.context.junit4.SpringRunner;

import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

@RunWith(SpringRunner.class)
@SpringBootTest
public class OrderGenericTest {

    @Autowired
    RedisTemplate redisTemplate;

    
    @Test
    public void genericOrderNo() {

        Set sns = new ConcurrentHashSet<>(50000);

        List list = new ArrayList<>(50);
        OrderSnUtil orderSnUtil =