Connection Refused when wrapping JMS Connection in ThreadLocal

Question

Running into an issue where connection.start() fails due to

java.net.ConnectException: Connection refused: connect

when I wrap my javax.jms.TopicConnection in a ThreadLocal, as follows:

private ThreadLocal<TopicConnection> createThreadLocalTopicConnection(final TopicConnectionFactory cf)
{
    return new ThreadLocal<TopicConnection>() {
        public TopicConnection result;

        protected synchronized TopicConnection initialValue() {
            try {
                // Returns a javax.jms.TopicConnection object.
                result = cf.createTopicConnection();
                result.start();
                return result;
            } catch (JMSException e) {
                throw new RuntimeException(e);
            }
        }

            protected void finalize() throws Throwable {
                if(result!=null) result.close();
            }
        };
    }

If I just create the TopicConnection as a bare static variable, it connects without any issues. Can anybody explain why it would work as a bare variable but when wrapped in a ThreadLocal it would fail? Google has failed me pretty spectacularly this time around.

score 0 · Answer 1 · answered Jul 26 '13 at 17:32

0

It's hard to say exactly why this is happening, but JMS clients are usually multi-threaded beasts, so I can see that this strategy might not be totally kosher.

JMS Connections are intended to be thread-safe, you you might want to just wrap your connection in a singleton or something. (JMS Sessions and below are not thread-safe and should not be shared by threads, so you might consider putting the session in a thread local if you're committed to this approach).

answered Jul 26 '13 at 17:32

Nicholas

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The reason I wrapped it in a ThreadLocal is because when I simply declared the connection as static I was getting some odd side-effect behavior where intra-app messages weren't being received while inter-app messages were working as expected. I am suspecting that some inter-thread configuration differences are the culprit. Working with ActiveMQ's PooledConnectionFactory resolves the issue, but I'm trying to avoid stepping outside of the javax.jms references already in my code – StormeHawke Jul 26 '13 at 17:44

score 0 · Answer 2 · answered Jul 26 '13 at 19:05

0

ThreadLocal would mean every Thread is getting it's own Connection. Do compare how many threads the application is spawning vs the number of connections in the ActivationSpec

answered Jul 26 '13 at 19:05

user1132593

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"ThreadLocal would mean every Thread is getting it's own Connection". That was kind of the point. Thanks though – StormeHawke Jul 26 '13 at 21:08

Connection Refused when wrapping JMS Connection in ThreadLocal

2 Answers2