基于Atomic原子类实现自定义格式生成唯一自增ID

思想：Id内存加锁+DB落库

 

菜鸡实现篇：

@Repository
public class IdMakerRepo extends Repo<IdMaker> {
    static Lock lock = new ReentrantLock();
    static Cache<Object, Object> localCahce = Caffeine.newBuilder().expireAfterAccess(1, TimeUnit.DAYS).build();


    public  String getId(String prefix) {
        return _getId(prefix);
    }

    private  String _getId(String prefix) {
        lock.lock();
        try {
            String name = prefix == null ? "tool__idmaker" : prefix;
            IdMaker idmaker = (IdMaker) localCahce.get(name, a -> {
                KPairIndex query = new KPairIndex();
                String s = $.date.toString(new Date(), "yyyy-MM-dd");
                query.setName(name);
                Date startDate = $.date.toDate(s, "yyyy-MM-dd");
                query._gt.setLastmodifytime(startDate);
                Date endDate = $.date.toDate(s, "yyyy-MM-dd");
                query._lt.setLastmodifytime(DateUtils.addDays(endDate, 1));
                IdMaker idMaker = null;
                List<IdMaker> idMakers = this.get(1, 1, query);
                if ($.list.isHasRow(idMakers)) {
                    idMaker = idMakers.get(0);
                }
                if (idMaker == null) {
                    StringBuilder sb = new StringBuilder();
                    sb.append(prefix);
                    sb.append($.date.toString(new Date(), "yyyyMMdd"));
                    sb.append("0001");
                    idMaker = new IdMaker(UUID.randomUUID().toString().replace("-", ""), 1, name, sb.toString());
                    this.save(idMaker);
                }
                return idMaker;
            });
            if (idmaker.getCount() == 0){
                idmaker.setCount(idmaker.getCount() + 1);
            }else{
                idmaker.upNo();
            }
            this.modify(idmaker);
            return idmaker.getNo();
        } finally {
            lock.unlock();
        }
    }
}


架构思想实现篇：

@Component
public class SeqUtil {

    @Autowired
    private SeqRepo seqRepo;

    private static SeqUtil seqUtil;

　　// 原子类
    private static final AtomicLong autoNum = new AtomicLong(1);
　　// 日期
　  private static String curDateStr;

　　// 项目每次启动初始化
    @PostConstruct
    public void init() {
        seqUtil = this;
        seqUtil.seqRepo = this.seqRepo;

        curDateStr = DateUtil.dateToStr(new Date(), DateUtil.DATE_FORMAT_DAFAULT);
        initSeq(curDateStr);
    }
　　
　　//初始化流程
    private static void initSeq(String curDateStr) {
        Seq seq = seqUtil.seqRepo.get(curDateStr);
        if(Objects.isNull(seq)){
            seqUtil.seqRepo.save(new Seq());
        }else{
            long nextAutoNo = seq.getAutoNo() + 100;
            autoNum.set(nextAutoNo);

            //更新
            seq.setAutoNo(nextAutoNo);
            seqUtil.seqRepo.modify(seq);
        }
    }

    public static String genTimeCode(String preFix){
        return genTimeCode(preFix, "yyyyMMdd");
    }

    private static String genTimeCode(String preFix, String dateFormat) {

        String curDate = DateUtil.dateToStr(new Date(), DateUtil.DATE_FORMAT_DAFAULT);
        if(!curDateStr.equals(curDate)){
            curDateStr = DateUtil.dateToStr(new Date(), DateUtil.DATE_FORMAT_DAFAULT);
            initSeq(curDateStr);
        }

        String seqNo = preFix + DateUtil.dateToStr(new Date(), dateFormat) + getAutoNum(autoNum.getAndIncrement());
        if(autoNum.get() % 100 == 0){
            Seq seq = seqUtil.seqRepo.get(DateUtil.dateToStr(new Date(), DateUtil.DATE_FORMAT_DAFAULT));
            seq.setAutoNo(autoNum.get());
            seqUtil.seqRepo.modify(seq);
        }
        return seqNo;
    }


    private static String getAutoNum(long autoNo){
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < 4 - String.valueOf(autoNo).length() ; i++) {
            builder.append("0");
        }

        return builder.append(autoNo).toString();
    }
}

model属性：

public class Seq extends Entity {
    private String id;
    private long autoNo; //自增编号

    //创建时间、更新时间
    private Date createTime;
    private Date lastModifyTime;

    public Seq(){
        this.id = DateUtil.dateToStr(new Date(), DateUtil.DATE_FORMAT_DAFAULT);
        this.autoNo = 1;
    }

    @Override
    public String getId() {
        return this.id;
    }

    public long getAutoNo() {
        return autoNo;
    }

    public void setAutoNo(long autoNo) {
        this.autoNo = autoNo;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public Date getLastModifyTime() {
        return lastModifyTime;
    }

}