Receiving pubsub messages with JSON Payload

Smack Smack Dev
1

I’m using smack-experimental-4.1.0-beta2-SNAPSHOT. On Subscribing side, how get JsonPacketExtension from ConfigurationEvent?

To contrast, on the Publishing side, constructing a PayloadItem with JsonPacktExtension to send using LeafNode is easy:

   JsonPacketExtension jasonPacketExtension = new JsonPacketExtension(myJsonObject.toString());

   PayloadItem(itemId, node, jasonPacketExtension); //...now use LeafNode's send method.

//Subscriber side code is based on PubSub example provided with Smack download

PubSubManager mgr = new PubSubManager(connection);
LeafNode node = mgr.getNode(“testNode”);
NodeConfigCoordinator nodeConfigCoordinator = new NodeConfigCoordinator();
node.addConfigurationListener(nodeConfigCoordinator);
node.subscribe(subscriberJID);

ConfigureForm form = new ConfigureForm(DataForm.Type.submit);
form.setAccessModel(AccessModel.open);
form.setDeliverPayloads(true); //Want payload
form.setNotifyRetract(true);
form.setPersistentItems(true);
form.setPublishModel(PublishModel.open);

node.sendConfigurationForm(form);

/**

  • …Nested class in a continuously running service that waits for subscription payloads
    */

class NodeConfigCoordinator implements NodeConfigListener {

@Override
public void handleNodeConfiguration(ConfigurationEvent configurationEvent) {

List packetExtensions = (List) configurationEvent.getExtensions();

for (PacketExtension packetExtension : packetExtensions) {

JsonPacketExtension jpe =JsonPacketExtension.from(packetExtension); ** //<<<<< Compiler NOT happy. How extract the JSON from PacketExention?**
//… Need to use jsonString contained in JaspnPackExtension

}

}

Error:(87, 61) java: method from in class org.jivesoftware.smackx.json.packet.JsonPacketExtension cannot be applied to given types;

required: org.jivesoftware.smack.packet.Packet

found: org.jivesoftware.smack.packet.PacketExtension

reason: actual argument org.jivesoftware.smack.packet.PacketExtension cannot be converted to org.jivesoftware.smack.packet.Packet by method invocation conversion

2

JsonPacketExtension jpe = PacketUtil.packetextensionFromCollection(packetExtensions, JsonPacketExtension.ELEMENT, JsonPacketExtension.NAMESPACE)

1 Like
3

I appreciate your help.

To summarize PacketUtil usage, below are two JSON Payload handlers for ConfigurationEvent and ItemPublishEvent:

class NodeConfigCoordinator implements NodeConfigListener {

@Override
public void handleNodeConfiguration(ConfigurationEvent configurationEvent) {

ConfigureForm configureForm = configurationEvent.getConfiguration();
Collection packetExtensions = configurationEvent.getExtensions();
JsonPacketExtension jpe = PacketUtil.packetExtensionfromCollection(packetExtensions, JsonPacketExtension.ELEMENT, JsonPacketExtension.NAMESPACE);
System.out.println(“handleNodeConfiguration: now writing to S3 bucket…”)

}

}

class ItemEventCoordinator implements ItemEventListener {

@Override
public void handlePublishedItems(ItemPublishEvent itemPublishEvent) {

Collection packetExtensions = itemPublishEvent.getItems();
JsonPacketExtension jpe = PacketUtil.packetExtensionfromCollection(packetExtensions, JsonPacketExtension.ELEMENT, JsonPacketExtension.NAMESPACE);
System.out.println(“handlePublishedItems: now writing to S3 bucket…”);

}

}