redis更新数据

/**
     * 更新redis数据
     *
     *
     */
    @Override
    public void updateRedis() {
        Map<String, CoreDevice> coreDeviceMap = new HashMap<>();

        if (coreDeviceMap.isEmpty()) {
            coreDeviceMap = coreDeviceService.list().stream()
                    .collect(Collectors.toMap(CoreDevice::getDeviceId, Function.identity()));
        }

        Set keyset = coreDeviceMap.keySet();
        for(Object key:keyset){
            String deviceJSon = null;
            try {
                deviceJSon = objectMapper.writeValueAsString(coreDeviceMap.get(key));
                stringRedisTemplate.opsForValue().set(key.toString(), deviceJSon, 30, TimeUnit.MINUTES);
            } catch (JsonProcessingException e) {
                e.printStackTrace();
            }
        }
//        stringRedisTemplate.opsForValue().set(deviceId, "", 2, TimeUnit.MINUTES);

    }