@Override
 public String validFlowbase(String flowbaseId) {
   Flowbase flowbase = flowbaseDao.getById(flowbaseId);
   String msg = "";
   if (flowbase == null) msg = "流程不存在";
   else {
     if (!flownodeDao.hasStartNode(flowbaseId)) {
       msg = "流程没有开始节点";
     } else if (!flownodeDao.hasEndNode(flowbaseId)) {
       msg = "流程没有结束节点";
     }
   }
   return msg;
 }
 @Override
 public void updateNodeAndLinkPosition(List<Flownode> flownodeList, List<Flowlink> flowlinkList) {
   for (Flownode flownode : flownodeList) {
     flownodeDao.updateNotNull(flownode);
   }
   for (Flowlink flowlink : flowlinkList) {
     flowlinkDao.updateNotNull(flowlink);
   }
 }