pre>
        <p>
    And, finally, we always abort the transaction if the transaction handle
    is not null. Note that immediately after committing our transaction, we
    set the transaction handle to null to guard against aborting a
    transaction that has already been committed.
</p>
        <pre class="programlisting">                } finally {
                    if (txn != null) {
                        try {
                            txn.abort();
                        } catch (Exception e) {
