判断一个元素在list集合内出现的次数
List<DeviceSpotCheck> deviceSpotCheckList = listMap.get(deviceCode); List<String> collect = deviceSpotCheckList.stream().map(DeviceSpotCheck::getCheckCode).collect(Collectors.toList()); if (Collections.frequency(collect,checkCode) >= 1){ failMsg.append("点检编码已存在该设备下,不允许重复,"); }
主要就是下面这行代码
Collections.frequency(collect,checkCode)