java 取list 前几条，限制list长度

方法1
用stream流

        List<OctvParkCamera> parkCameraList = octvParkCameraMapper.selectOctvParkCameraList(octvParkCamera);
        List<OctvParkCamera> newList=parkCameraList.stream().limit(4).collect(Collectors.toList());

方法2

        if (parkCameraList.size() > 4) {
            List<OctvParkCamera>  newList = parkCameraList.subList(0, 4);
            return newList;
        } else {
            return parkCameraList;
        }