Example usage for javax.persistence EntityManager setProperty

Introduction

In this page you can find the example usage for javax.persistence EntityManager setProperty.

Prototype

public void setProperty(String propertyName, Object value);

Source Link

Document

Set an entity manager property or hint.

Usage

From source file:gov.osti.services.Metadata.java

/**
 * Obtain a reserved DOI value if possible.
 *
 * @return a DoiReservation if successful, or null if not
 *//*from w w w  .ja  v  a 2  s.c  o  m*/
private static DoiReservation getReservedDoi() {
    EntityManager em = DoeServletContextListener.createEntityManager();
    // set a LOCK TIMEOUT to prevent collision
    em.setProperty("javax.persistence.lock.timeout", 5000);

    try {
        em.getTransaction().begin();

        DoiReservation reservation = em.find(DoiReservation.class, DoiReservation.TYPE,
                LockModeType.PESSIMISTIC_WRITE);

        if (null == reservation)
            reservation = new DoiReservation();

        reservation.reserve();

        em.merge(reservation);

        em.getTransaction().commit();

        // send it back
        return reservation;
    } catch (PessimisticLockException | LockTimeoutException e) {
        log.warn("DOI Reservation, unable to obtain lock.", e);
        return null;
    } finally {
        em.close();
    }
}

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