修复设备列表bug2

sample/src/main/java/com/dji/sample/manage/service/impl/DeviceServiceImpl.java

@@ -670,9 +670,11 @@ public class DeviceServiceImpl extends ServiceImpl<IDeviceMapper, DeviceEntity>
         DeviceDTO device = devicesList.get(0);
         device.setStatus(deviceRedisService.checkDeviceOnline(sn));
         // 查询 无人机
-        List<DeviceDTO> childrenList = this.getDevicesByParams(DeviceQueryParam.builder().deviceSn(device.getChildDeviceSn()).build());
-        if (!childrenList.isEmpty()) {
-            device.setChildren(childrenList.get(0));
+        if (StringUtils.hasText(device.getChildDeviceSn())) {
+            List<DeviceDTO> childrenList = this.getDevicesByParams(DeviceQueryParam.builder().deviceSn(device.getChildDeviceSn()).build());
+            if (!childrenList.isEmpty()) {
+                device.setChildren(childrenList.get(0));
+            }
         }
         return Optional.of(device);
     }