fix bug 类型转换异常

ad-engine-service/src/main/java/com/tzld/piaoquan/ad/engine/service/predict/impl/PredictModelServiceImpl.java

@@ -88,7 +88,8 @@ public class PredictModelServiceImpl implements PredictModelService {
             midGroup = "mean_group";
         }
 
-        String[] noAdMidGroupList=(String[]) ((JSONArray) abtestParam.get("no_ad_mid_group_list")).toArray();
+        String[] noAdMidGroupList=new String[0];
+        noAdMidGroupList=((JSONArray) abtestParam.get("no_ad_mid_group_list")).toArray(noAdMidGroupList);
 
         boolean inNoAdGroup = false;
         for (String group : noAdMidGroupList) {