StompConnection的ActiveMQ寄存器侦听器

Question

I'm using a variation of the example at http://svn.apache.org/repos/asf/activemq/trunk/assembly/src/release/example/src/StompExample.java to receive message from a queue. What I'm trying to do is to keep listening to a queue and perform some action upon reception of a new message. The problem is that I couldn't find a way to register a listener to any of the related objects. I've tried something like:

public static void main(String args[]) throws Exception {
    StompConnection connection = null;
    try {
        connection = new StompConnection();
        connection.open("localhost", 61613);
        connection.connect("admin", "activemq");
        connection.subscribe("/queue/worker", Subscribe.AckModeValues.AUTO);
        while (true) {
            StompFrame message = connection.receive();
            System.out.println(message.getBody());
        }
    } catch (UnknownHostException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (connection != null) {
            connection.disconnect();
        }
    }
}

but this doesn't work as a time out occurs after a few seconds ( java.net.SocketTimeoutException: Read timed out ). Is there anything I can do to indefinitely listen to this queue?

Answer 1

ActiveMQ's StompConnection class is a relatively primitive STOMP client. Its not capable of async callbacks on Message or for indefinite waits. You can pass a timeout to receive but depending on whether you are using STOMP v1.1 it could still timeout early if a heart-beat isn't received in time. You can of course always catch the timeout exception and try again.

For STOMP via Java you're better off using StompJMS or the like which behaves like a real JMS client and allows for async Message receipt.

Answer 2

@Tim Bish: I tried StompJMS, but couldn't find any example that I could use (maybe you can provide a link). I 'fixed' the problem by setting the timeout to 0 which seems to be blocking.

Answer 3

even i was facing the same issue.. you can fix this by adding time out to your receive() method.

Declare a long type variable.

long waitTimeOut = 5000;   //this is 5 seconds

now modify your receive function like below.

StompFrame message = connection.receive(waitTimeOut);

This will definitely work.