code: public final void rollback() throws XAException
      {
          if (tc.isEntryEnabled()) Tr.entry(tc, "rollback", _resource);
          if (tcSummary.isDebugEnabled()) Tr.debug(tcSummary, "rollback", this);
  
          try
          {
              _resource.rollback(_xid);
  
  			// Record the vote.
  			// _completedCommit defaults to false.
  			_vote = JTAResourceVote.rollback;
          }
          catch(XAException xae)
          {
  			// Record the completion XA return code
  			_completionXARC = xae.errorCode;
  
  			throw xae;
          }
          finally
          {
              if (tc.isEntryEnabled()) Tr.exit(tc, "rollback");
              if (tcSummary.isDebugEnabled()) Tr.debug(tcSummary, "rollback result: " + 
                                                                  XAReturnCodeHelper.convertXACode(_completionXARC));
          }
      }
docs: Rollback a transaction.
  
  @exception SystemException
  an unindentified error has been reported
  by the resource manager