javax.persistence.TransactionRequiredException: no transaction is in progress

javax.persistence.TransactionRequiredException: no transaction is in progress

I resolved this issue as follows

    @Transactional(readOnly = false)

    public void updateTimeStamp (Long id, long timeStamp) {

       Alert rec = Alert .findById(id);

        try {

            if (!Alert .em().getTransaction().isActive()) {

            Alert .em().getTransaction().begin();

            }

            rec.setTimeStamp(timeStamp);;

            rec.save();

            Alert .em().getTransaction().commit();

        } catch (Exception e) {

            Logger.error(e, "Error: ");

        }

    }

Hope this helps :)