"konstantin.ermakov" wrote : Hi!
|
| As far as I understood, after update() it is not guaranteed, that the data
is in database and commit event already happened. So, as I have the fat clients
it can be the case, that after update() was called, getObject() still returns
the old entity.
|
| My question is - is it guarateed, that after the afterCompletion() method
the database commit already happened, and it is safe to call getObject() to
receive the new data?
|
I think yes, when you use TXed messages to notify your clients. E.g. here the
meat (aka main things) how I use it:
| public class MsgProducer {
| private static HashMap seq =
| new HashMap();
| ...
| /**
| * Simple container for recording queue parameters.
| *
| * @author Jens Elkner
| * @version $Revision$
| */
| public static class QueueParams {
| Connection con;
| Session session;
| MessageProducer producer;
|
| QueueParams(Connection con, Session session, MessageProducer
producer) {this.con = con;
| this.session = session;
| this.producer = producer;
| }
|
| void destroy() {
| if (con != null) {
| try {
| con.stop();
| } catch (JMSException e) {
| // ignore
| }
| }
| if (session != null) {
| try {
| session.close();
| } catch (JMSException e) {
| // ignore
| }
| }
| if (con != null) {
| try {
| con.close();
| } catch (JMSException e) {
| // ignore
| }
| }
| }
| }
|
| /**
| * Create a message producer for the given destination.
| *
| * @param destination topic to use
| * @param txwhether to use a transaction scoped session
| * @return null on error, the message producer otherwise.
| */
| private static QueueParams createNewSession(String destination, boolean
tx)
| {
| try {
| ctx = new InitialContext();
| // we let the destination decide, whether it is a
| // Queue- or TopicConnectionFactory
| ConnectionFactory cf = (ConnectionFactory)
| ctx.lookup("java:/JmsXA");
| // create a Connection using the ConnectionFactory (it is not
| // necessary to start the Connection if messages are only sent)
| Connection tc = cf.createConnection();
| // create a Session using the Connection: Transaction +
| // Auto Acknowledge of the Messages
| Session s = tc.createSession(tx,
| tx ? Session.SESSION_TRANSACTED : Session.AUTO_ACKNOWLEDGE);
| // look up the Destination (either Queue or Topic) to which we
want
| // to connect in JNDI
| Destination dst = (Destination) ctx.lookup(destination);
| // create a message producer by the session and destination
acquired
| // above
| MessageProducer producer = s.createProducer(dst);
| if (producer != null) {
| params = new QueueParams(tc, s, producer);
| }
| } catch (Exception e) {
| log.error(e.getLocalizedMessage());
| failed = true;
| }
| if (failed && params != null) {
| params.destroy();
| params = null;
| }
| return params;
| }
|
| /**
| * Send a message to the given destination.
| *
| * @param destination name of the queue/topic - e.g. "topic/foo" or
| * "queue/bar".
| * @param list list of CRUD events
| */
| public static void send(String destination, CrudEventList list) {
| if (destination == null || list == null || list.getSize() == 0) {
| return;
| }
| QueueParams q = createNewSession(destination, true);
| if (q == null) {
| log.error("Unable to deliver message to '" + destination + "'");
| return;
| }
| try {
| ObjectMessage m = q.session.createObjectMessage(list);
| long msgId = getNextId(destination);
| m.setLongProperty("seq", msgId);
| if (log.isDebugEnabled()) {
| log.debug("sending CRUD message " + msgId + " to " +
destination);
| }
|
