src/org/nutz/dao/impl/NutTxDao.java
public NutTxDao rollback(String id) {
        if (debug)
            log.debugf("rollback id=%s", id);
        try {
            Savepoint sp = sps.getAs(id, Savepoint.class);
            if (sp != null)
                conn.rollback(sp);
            else
                log.debug("Null Savepoint found, skip, id=" + id);
        }
        catch (Throwable e) {
        }
        return this;
    }
public NutTxDao rollback(String id) {
        if (debug)
            log.debugf("rollback id=%s", id);
        try {
            Savepoint sp = sps.getAs(id, Savepoint.class);
            if (sp != null)
                conn.rollback(sp);
            else
                log.debug("Null Savepoint found, skip, id=" + id);
        }
        catch (Throwable e) {
        }
        return this;
    }
回滚事务

@param id
回滚点
@return 原对象