@Component
public class RedisIdWorker {
    /**
     * 開始時間戳
     */
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    /**
     * 序列號的位數(shù)
     */
    private static final int COUNT_BITS = 32;

    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix) {
        // 1.生成時間戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        // 2.生成序列號
        // 2.1.獲取當(dāng)前日期，精確到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        // 2.2.自增長
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        // 3.拼接并返回
        return timestamp << COUNT_BITS | count;
    }
}

@Autowired
private RedisIdWorker redisIdWorker;

private ExecutorService es = Executors.newFixedThreadPool(500);
@Test
public void testWorkerId() throws InterruptedException {
    CountDownLatch latch = new CountDownLatch(300);
    Runnable task = () -> {
        for (int i = 0; i < 100; i++) {
            long id = redisIdWorker.nextId("order");
            System.out.println("id = " + id);
        }
        latch.countDown();
    };

    long begin = System.currentTimeMillis();
    for (int i = 0; i < 300; i++) {
        es.submit(task);
    }
    latch.await();
    long end = System.currentTimeMillis();
    System.out.println("times = " + (end- begin));
}

@Service
public class VoucherServiceImpl extends ServiceImpl<VoucherMapper, Voucher> implements IVoucherService {
    // 該類無代碼，直接MyBatis-Plus繼承實現(xiàn)類 即可，自動完成持久化
    @Autowired
    private ISeckillVoucherService seckillVoucherService;

    @Override
    public ResultBean<List<Voucher>> queryVoucherOfShop(Long shopId) {
        // 查詢優(yōu)惠券信息
        List<Voucher> vouchers = getBaseMapper().queryVoucherOfShop(shopId);
        // 返回結(jié)果
        return ResultBean.create(0, "success", vouchers);
    }

    @Override
    public void addSeckillVoucher(Voucher voucher) {
        // 保存優(yōu)惠券
        save(voucher);
        // 保存秒殺信息
        SeckillVoucher seckillVoucher = new SeckillVoucher();
        seckillVoucher.setVoucherId(voucher.getId());
        seckillVoucher.setStock(voucher.getStock());
        seckillVoucher.setBeginTime(voucher.getBeginTime());
        seckillVoucher.setEndTime(voucher.getEndTime());
        seckillVoucherService.save(seckillVoucher);
    }
}

@RestController
@CrossOrigin
@RequestMapping("/voucher")
public class VoucherController {

    @Autowired
    private IVoucherService voucherService;
    
    /**
     * 新增秒殺券
     * @param voucher 優(yōu)惠券信息，包含秒殺信息
     * @return 優(yōu)惠券id
     */
    @PostMapping("seckill")
    public ResultBean addSeckillVoucher(@RequestBody Voucher voucher) {
        voucherService.addSeckillVoucher(voucher);
        return Result.ok(voucher.getId());
    }
}

@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder>  implements IVoucherOrderService {


    @Autowired
    private ISeckillVoucherService seckillVoucherService;

    @Autowired
    private RedisIdWorker redisIdWorker;

    @Override
    @Transactional
    public Result seckillVoucher(Long voucherId) {
        //1. 查詢優(yōu)惠卷
        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
        //2. 判斷秒殺是否開始 開始時間大于當(dāng)前時間表示未開始搶購
        if (seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())) {
            return Result.fail("秒殺尚未開始！");
        }
        //3. 判斷秒殺是否結(jié)束
        if (seckillVoucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒殺已經(jīng)結(jié)束！");
        }
        //4. 判斷庫存是否充足
        if (seckillVoucher.getStock() < 1) {
            return Result.fail("庫存不足！");
        }

        Long userId = UserHolder.getUser().getId();
        //5. 查詢訂單
        //5.1 查詢訂單
        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        //5.2 判斷并返回
        if (count > 0) {
            return Result.fail("用戶已經(jīng)購買過！");
        }

        //6. 扣減庫存
        boolean success = seckillVoucherService.update().setSql("stock = stock -1")
                .eq("voucher_id", voucherId).update();
        if (!success) {
            return Result.fail("庫存不足！");
        }

        //7. 創(chuàng)建訂單
        VoucherOrder voucherOrder = new VoucherOrder();
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        //8. 返回訂單id
        return Result.ok(orderId);
    }
}

@RestController
@CrossOrigin
@RequestMapping("/voucher_order")
public class VoucherOrderController {

    @Autowired
    private IVoucherOrderService voucherOrderService;

    @PostMapping("seckill/{id}")
    public Result seckillVoucher(@PathVariable("id") Long voucherId) {
        return voucherOrderService.seckillVoucher(voucherId);
    }
}

 if (voucher.getStock() < 1) {
        // 庫存不足
        return Result.fail("庫存不足！");
    }
    //5，扣減庫存
    boolean success = seckillVoucherService.update()
            .setSql("stock= stock -1")
            .eq("voucher_id", voucherId).update();
    if (!success) {
        //扣減庫存
        return Result.fail("庫存不足！");
    }

int varNum;
do {
    varNum = this.getIntVolatile(var1, var2);
} while(!this.compareAndSwapInt(var1, var2, var5, var5 + var4));

return var5;

boolean success = seckillVoucherService.update()
            .setSql("stock= stock -1")
            .eq("voucher_id", voucherId).update().gt("stock",0); //where id = ? and stock > 0

int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
if (count > 0) {
    return Result.fail("用戶已經(jīng)購買過！");
}

@Override
    public Result seckillVoucher(Long voucherId) {
        //1. 查詢優(yōu)惠卷
        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
        //2. 判斷秒殺是否開始 開始時間大于當(dāng)前時間表示未開始搶購
        if (seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())) {
            return Result.fail("秒殺尚未開始！");
        }
        //3. 判斷秒殺是否結(jié)束
        if (seckillVoucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒殺已經(jīng)結(jié)束！");
        }
        //4. 判斷庫存是否充足
        if (seckillVoucher.getStock() < 1) {
            return Result.fail("庫存不足！");
        }

        Long userId = UserHolder.getUser().getId();
        synchronized (userId.toString().intern()) {
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId, userId);
        }
    }

    @Transactional
    @Override
    public Result createVoucherOrder(Long voucherId, Long userId) {
        //5. 查詢訂單
        //5.1 查詢訂單
        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        //5.2 判斷并返回
        if (count > 0) {
            return Result.fail("用戶已經(jīng)購買過！");
        }

        //6. 扣減庫存
        boolean success = seckillVoucherService.update().setSql("stock = stock -1")
                .eq("voucher_id", voucherId).gt("stock", 0).
                update();
        if (!success) {
            return Result.fail("庫存不足！");
        }


        //7. 創(chuàng)建訂單
        VoucherOrder voucherOrder = new VoucherOrder();
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        //8. 返回訂單id
        return Result.ok(orderId);
    }

@EnableAspectJAutoProxy(exposeProxy = true)