fix bug

pcloud-common/src/main/java/com/pcloud/common/utils/ListUtils.java

@@ -70,18 +70,21 @@ public class ListUtils {
     }
 
     public static <T> List<T>groupList4SQL(ListForInSQL<T> listForInSQL,List<Long>idList){
+        if(idList==null || idList.size()==0){
+            return new ArrayList<>();
+        }
         HashSet<Long>idSet = new HashSet<>(idList);
         idList.clear();
         idList.addAll(idSet);
         List<T>result = new ArrayList<>();
-        if(idList!=null && idList.size()>500){
+        if(idList.size()>500){
             List<List<Long>> lists = groupList(idList);
             for (List<Long> list : lists) {
                 List<T> tempList = listForInSQL.processSQL(list);
                 result.addAll(tempList);
             }
             return result;
-        }else if(idList != null && idList.size()>0){
+        }else if(idList.size()>0){
             return listForInSQL.processSQL(idList);
         }else{
             return new ArrayList<>();