Question

I am getting java.util.concurrentmodificationexception for my implementation below

try{
         Date fromDate = new Date().parse("yyyy-MM-dd", SfromDate);
         Date toDate = new Date().parse("yyyy-MM-dd", StoDate); 
         def sTblList = this.getMonths(SfromDate,StoDate)
        def resourceInstance=Resources.get(res_id);
        sTblList.each{
         def OnemonthList=it.createCriteria().get {   
            eq('graresource',resourceInstance)
            between('currentdate', fromDate, toDate)           
            projections {  
            sum(sumCol,'t_cnt')
            groupProperty(groupCol)
            order('t_cnt', 'desc')
            maxResults(maxCount)
                }                  
            }      
            if (OnemonthList)
            sumMap.addAll(OnemonthList)
          }

            return sumMap
    }
       catch(Exception e){
           log.error("Error in SummaryUtilsService:getTop10UsersChart:" + e)
       }

Is it because I am try to group on an aggregate property, and something wrong with this syntax?

Answer 1

Your sTblList is getting modified somewhere else. This happens if the reference is shared among different threads. Try synchronizing the block.