check if old panel instance is null before recovering old parameters

kanban-console/src/main/java/com/uas/kanban/service/impl/PanelInstanceServiceImpl.java

@@ -397,20 +397,23 @@ public class PanelInstanceServiceImpl extends BaseService<PanelInstance> impleme
     }
 
     /**
-     * 根据用户和面板，删除相应的实例
+     * 生成面板实例
      *
-     * @param panelCode 面板 code
+     * @param panelCode        面板 code
+     * @param oldPanelInstance 旧的面板实例
      * @return 面板实例
      */
-    private PanelInstance generateInstance(@NotEmpty("panelCode") String panelCode, @NotEmpty("oldPanelInstance") PanelInstance oldPanelInstance) {
+    private PanelInstance generateInstance(@NotEmpty("panelCode") String panelCode, PanelInstance oldPanelInstance) {
         Panel panel = panelDao.checkExist(panelCode);
         PanelInstance panelInstance = new PanelInstance();
         panelInstance.setUserCode(SystemSession.getUser().codeNotEmpty());
         panelInstance.setPanelCode(panelCode);
         panelInstance.setPanelVersion(panel.getVersion());
         // 切换频率、刷新频率
-        panelInstance.setSwitchFrequency(oldPanelInstance.getSwitchFrequency());
-        panelInstance.setRefreshFrequency(oldPanelInstance.getRefreshFrequency());
+        if (oldPanelInstance != null) {
+            panelInstance.setSwitchFrequency(oldPanelInstance.getSwitchFrequency());
+            panelInstance.setRefreshFrequency(oldPanelInstance.getRefreshFrequency());
+        }
         initSwitchFrequence(panelInstance);
         panelInstance.toParameters(generateParameters(panelCode));
         List<Kanban> kanbans = kanbanDao.findByPanelCode(panelCode);
@@ -418,7 +421,9 @@ public class PanelInstanceServiceImpl extends BaseService<PanelInstance> impleme
             throw new IllegalStateException("面板 '" + panel.getName() + "' 未关联看板");
         }
         panelInstance.initKanbanCodes(kanbans);
-        recoverOldParameters(panelInstance, oldPanelInstance);
+        if (oldPanelInstance != null) {
+            recoverOldParameters(panelInstance, oldPanelInstance);
+        }
         return panelInstanceDao.save(panelInstance);
     }