public boolean delAccount(Account account) {
   int res = mapper.delAccount(account.getId());
   return res > 0;
 }
 public boolean updateUser(Account account) {
   int res = mapper.updateAccount(account.getUsername(), account.getId());
   return res > 0;
 }
 public boolean saveAccount(Account account) {
   int res = mapper.saveAccount(account.getUsername());
   return res > 0;
 }