controller层

@GetMapping("/reminder/{id}")
    public Result Remainder(@PathVariable("id") Long id){
        orderService.remainder(id);
        return Result.success();
    }

实现类

    @Override
    public void remainder(Long id) {
        Orders ordersDB = orderMapper.getById(id);

        // 校验订单是否存在，并且状态为4
        if (ordersDB == null) {
            throw new OrderBusinessException(MessageConstant.ORDER_STATUS_ERROR);
        }
        HashMap map = new HashMap();
        map.put("type",2);
        map.put("orderId",id);
        map.put("content","订单号" + ordersDB.getNumber());
        webSocketServer.sendToAllClient(JSON.toJSONString(map));

    }