指示牌列表，如果是空，返回空数组

src/main/java/com/fdkankan/scene/service/impl/SceneEditInfoExtServiceImpl.java

@@ -195,16 +195,19 @@ public class SceneEditInfoExtServiceImpl extends ServiceImpl<ISceneEditInfoExtMa
     @Override
     public JSONObject listBillboards(BaseSceneParamVO param) throws Exception {
 
+        JSONObject result = new JSONObject();
+        List<JSONObject> tags = new ArrayList<>();
+        List<JSONObject> styles = new ArrayList<>();
         ScenePlus scenePlus = scenePlusService.getScenePlusByNum(param.getNum());
         SceneEditInfoExt sceneEditInfoExt = this.getByScenePlusId(scenePlus.getId());
         if(sceneEditInfoExt.getBillboards() == CommonStatus.NO.code().intValue()){
-            return null;
+            result.put("tags", tags);
+            result.put("styles", styles);
+            return result;
         }
 
         this.syncBillboardsFromFileToRedis(param.getNum());
 
-        JSONObject result = new JSONObject();
-
         //获取指示牌数据
         String key = String.format(RedisKey.SCENE_BILLBOARDS, param.getNum());
         List<String> list = redisUtil.hgetValues(key);
@@ -217,7 +220,7 @@ public class SceneEditInfoExtServiceImpl extends ServiceImpl<ISceneEditInfoExtMa
             return tagBean;
         }).collect(Collectors.toList());
         sortList.sort(Comparator.comparingLong(TagBean::getCreateTime).reversed());
-        List<JSONObject> tags = sortList.stream().map(item -> item.getTag()).collect(Collectors.toList());
+        tags = sortList.stream().map(item -> item.getTag()).collect(Collectors.toList());
         result.put("tags", tags);
 
         //获取图标数据
@@ -233,7 +236,7 @@ public class SceneEditInfoExtServiceImpl extends ServiceImpl<ISceneEditInfoExtMa
             return tagBean;
         }).collect(Collectors.toList());
         sortList.sort(Comparator.comparingLong(TagBean::getCreateTime).reversed());
-        List<JSONObject> styles = sortList.stream().map(item -> item.getTag()).collect(Collectors.toList());
+        styles = sortList.stream().map(item -> item.getTag()).collect(Collectors.toList());
         result.put("styles", styles);
 
         return result;