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RosJava Tutorial Integration / Multiple Listeners

asked 2012-01-17 10:08:15 -0500

stevefturner gravatar image

updated 2012-01-18 02:01:54 -0500

I have a problem with topic publisher/subscriber integration in RosJava when using the rosjava version of RosCore. I can execute the following test successfully where multiple subscribers attach to a publisher.

public void testOnePublisherToManySubscriber() throws InterruptedException {
        nodeConfiguration.setNodeName("publisher");
        Node publisherNode = nodeFactory.newNode(nodeConfiguration);

        CountDownPublisherListener<org.ros.message.std_msgs.String> publisherListener =
            CountDownPublisherListener.newDefault();
        Publisher<org.ros.message.std_msgs.String> publisher =
            publisherNode.newPublisher("foo", "std_msgs/String");
        publisher.addListener(publisherListener);

        final org.ros.message.std_msgs.String helloMessage = new org.ros.message.std_msgs.String();
        helloMessage.data = "Hello, ROS!";

        final CountDownLatch messageReceived = new CountDownLatch(1);
        nodeConfiguration.setNodeName("subscriber");
        Node subscriberNode = nodeFactory.newNode(nodeConfiguration);

        CountDownSubscriberListener<org.ros.message.std_msgs.String> subscriberListener =
            CountDownSubscriberListener.newDefault();

        CountDownSubscriberListener<org.ros.message.std_msgs.String> subscriberListener2 =
                CountDownSubscriberListener.newDefault();

        Subscriber<org.ros.message.std_msgs.String> subscriber1 =
            subscriberNode.newSubscriber("foo", "std_msgs/String");
        subscriber1.addMessageListener(new MessageListener<org.ros.message.std_msgs.String>() {
          @Override
          public void onNewMessage(org.ros.message.std_msgs.String message) {
            assertEquals(helloMessage, message);
            messageReceived.countDown();
          }
        });
        subscriber1.addSubscriberListener(subscriberListener);

        Subscriber<org.ros.message.std_msgs.String> subscriber2 =
                subscriberNode.newSubscriber("foo", "std_msgs/String");
            subscriber2.addMessageListener(new MessageListener<org.ros.message.std_msgs.String>() {
              @Override
              public void onNewMessage(org.ros.message.std_msgs.String message) {
                assertEquals(helloMessage, message);
                messageReceived.countDown();
              }
            });
            subscriber2.addSubscriberListener(subscriberListener2);

        assertTrue(publisherListener.awaitMasterRegistrationSuccess(1, TimeUnit.SECONDS));
        assertTrue(subscriberListener.awaitMasterRegistrationSuccess(1, TimeUnit.SECONDS));

        RepeatingPublisher<org.ros.message.std_msgs.String> repeatingPublisher =
            new RepeatingPublisher<org.ros.message.std_msgs.String>(publisher, helloMessage, 1000,
                executorService);
        repeatingPublisher.start();

        assertTrue(messageReceived.await(1, TimeUnit.SECONDS));

        repeatingPublisher.cancel();
        publisher.shutdown();
        subscriber1.shutdown();
        subscriber2.shutdown();
      }

However, if I fire up a RosCore on my own with something like:

  public static void main(String[] argv){
        RosCore core;
        if(argv.length == 1)
            core = newPublic(Integer.valueOf(argv[0]));
        else
            core = newPublic(11311);

        core.start();
      }

And then I use RosRun to execute the Talker node, it registers successfully. But then if I attempt to start multiple listeners an after the first fail. Subsequently... other pub/sub features fail to work properly. For example, starting a listener prior to a publisher. What am I doing wrong?

I'm executing the code in Eclipse on Windows, where I execute RosRun and then pass the package as an argument. After executing the second listener I get the following from RosCore:

Jan 17, 2012 5:02:11 PM org.ros.internal.node.server.MasterServer start
INFO: Starting master server.
Jan 17, 2012 5:02:20 PM org.ros.internal.node.server.MasterServer registerPublisher
INFO: Registering publisher: PublisherIdentifier<SlaveIdentifier</talker, http://127.0.0.1:55060>, TopicIdentifier</chatter>>
Jan 17, 2012 5:02:20 PM org.ros.internal.node.server.MasterServer publisherUpdate
INFO: Publisher update: /chatter
Jan 17, 2012 5:02:20 PM org.ros.internal.node.server.MasterServer registerPublisher
INFO: Registering publisher: PublisherIdentifier<SlaveIdentifier</talker, http://127.0.0.1:55060>, TopicIdentifier</rosout>>
Jan 17, 2012 5:02:20 PM org.ros.internal.node.server.MasterServer publisherUpdate
INFO: Publisher update: /rosout
Jan 17, 2012 5:02:26 PM org.ros.internal.node.server.MasterServer registerPublisher
INFO: Registering publisher: PublisherIdentifier<SlaveIdentifier</Listener1, http://127.0.0.1:55070>, TopicIdentifier</rosout>>
Jan ...
(more)
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Comments

I've narrowed it down to a the publisherUpdate call in SlaveClient. If I attempt to register two publishers on the same topic on two different hosts, I get the failure: org.apache.xmlrpc.common.XmlRpcInvocationException: Failed to invoke method registerPublisher in class org.ros.internal.node.xmlrpc
stevefturner gravatar image stevefturner  ( 2012-01-18 06:53:14 -0500 )edit

1 Answer

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answered 2012-01-23 01:26:51 -0500

damonkohler gravatar image

I think this is a bug in the current rosjava implementation of roscore at head. The released version of rosjava should not have this problem. We're working to resolve this at head.

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Asked: 2012-01-17 10:08:15 -0500

Seen: 795 times

Last updated: Jan 23 '12