Thank you! That worked. I have pushed an update to my code, and I've been able to send a message to NATS from a REST endpoint, and receive a message from NATS via an MDB.
I still need to extract the cluster ID and client ID into properties for the resource adapter, and of course, try and write up how this works. Code is here: https://github.com/jgallimore/tomee-chatterbox/tree/nats, but I'll merge it in once I have done these couple of changes. One other thing on my mind is that I'd like to try and find some way to make all this easier. If you've used JMS, you've used JCA, possibly without realizing it, but the spec still feels very hard to get into - I wonder if there is anything we can propose in that regard to try and make creating simple connectors a bit easier. Jon On Wed, Jun 9, 2021 at 4:31 PM Matthew Broadhead <[email protected]> wrote: > hi, it was my fault putting a confusing value in the docker compose > file. it should work like this > > StreamingConnectionFactory cf = new > StreamingConnectionFactory(new > Options.Builder().natsUrl("nats://localhost:4222") > .clusterId("yourclientid").clientId("anything").build()); > > but you could change the docker-compose.yml to have a -cid of > yourclusterid and then do this > > StreamingConnectionFactory cf = new > StreamingConnectionFactory(new > Options.Builder().natsUrl("nats://localhost:4222") > .clusterId("yourclusterid").clientId("yourclientid").build()); > > On 09/06/2021 17:15, Jonathan Gallimore wrote: > > Thanks. If I can get that test going, I can probably get the rest > working. > > I suspect there are some other bugs in there. > > > > Jon > > > > On Wed, Jun 9, 2021 at 4:04 PM Matthew Broadhead > > <[email protected]> wrote: > > > >> Thanks I will have a look now > >> > >> On 09/06/2021 15:19, Jonathan Gallimore wrote: > >>> Ok, I'm stuck. If I boot up a NATS server with your docker-compose.yml > >>> file, and run the following test: > >>> > >>> @Test > >>> public void testShouldConnect() throws Exception { > >>> StreamingConnectionFactory cf = new > >>> StreamingConnectionFactory(new > >>> Options.Builder().natsUrl("nats://localhost:4222") > >>> > >> .clusterId("cluster-id").clientId("yourclientid").build()); > >>> final StreamingConnection connection = cf.createConnection(); > >>> Assert.assertNotNull(connection); > >>> > >>> connection.close(); > >>> } > >>> > >>> It fails with a timeout. > >>> > >>> I monitored the connection with wireshark, and see the following > >>> > >>> < = from server to client > >>>> = from client to server > >>> <INFO > >>> > >> > <{"server_id":"NDMRYDSGUSH2QR6SZWMFB44ND5CODXGKNYTQ5IPLUGYUDBI6G54CIGF6","server_name":"NDMRYDSGUSH2QR6SZWMFB44ND5CODXGKNYTQ5IPLUGYUDBI6G54CIGF6","version":"2.1.4","proto":1,"git_commit":"fb009af","go":"go1.13.7","host":"0.0.0.0","port":4222,"max_payload":1048576,"client_id":10} > >>>> CONNECT > >> > {"lang":"java","version":"2.6.5","name":"yourclientid","protocol":1,"verbose":false,"pedantic":false,"tls_required":false,"echo":true} > >>>> PING > >>> <PONG > >>>> SUB _STAN.acks.LP4bdY88abuVJ19Qo5HVuk 1 > >>>> SUB _INBOX.LP4bdY88abuVJ19Qo5HVn8 2 > >>>> SUB _INBOX.LP4bdY88abuVJ19Qo5HVqw 3 > >>>> SUB _INBOX.F0vVy1N0sQM3xseeEWMIAL.* 4 > >>>> PUB _STAN.discover.cluster-id > >>> _INBOX.F0vVy1N0sQM3xseeEWMIAL.F0vVy1N0sQM3xseeEWMISH 75 > >> > .yourclientid.._INBOX.LP4bdY88abuVJ19Qo5HVn8..".LP4bdY88abuVJ19Qo5HVjK(.0. > >>> <PING > >>>> PONG > >>>> UNSUB 1 > >>>> UNSUB 2 > >>>> UNSUB 3 > >>> So there does appear to be some communication between my test and the > >> NATS > >>> server - I have no idea why it times out. > >>> > >>> My code is here if you want to have a go: > >>> https://github.com/jgallimore/tomee-chatterbox/tree/nats > >>> > >>> Jon > >>> > >>> On Wed, Jun 9, 2021 at 11:56 AM Jonathan Gallimore < > >>> [email protected]> wrote: > >>> > >>>> Nervermind, I figured out my mistake. I'll post back when I have > >> something > >>>> going. > >>>> > >>>> Jon > >>>> > >>>> On Wed, Jun 9, 2021 at 11:44 AM Jonathan Gallimore < > >>>> [email protected]> wrote: > >>>> > >>>>> I think I have something wired up, but when executing this: > >>>>> > >>>>> cf = new > >>>>> StreamingConnectionFactory(new > >>>>> Options.Builder().natsUrl(baseAddress) > >>>>> > >>>>> .clusterId("cluster-id").clientId("client-id").build()); > >>>>> > >>>>> connection = cf.createConnection(); > >>>>> > >>>>> > >>>>> connection is null. Any pointers? > >>>>> > >>>>> Jon > >>>>> > >>>>> On Wed, Jun 9, 2021 at 8:16 AM Matthew Broadhead > >>>>> <[email protected]> wrote: > >>>>> > >>>>>> i have never used a JCA adapter before. is it loaded in using the > >>>>>> tomee.xml as a Resource? and then injected into a singleton for > >>>>>> subscribing to messages? > >>>>>> > >>>>>> On 08/06/2021 17:15, Jonathan Gallimore wrote: > >>>>>>> Definitely sounds like a good case for a JCA adapter. I'll take a > >> quick > >>>>>>> swing at hooking up an example for you. > >>>>>>> > >>>>>>> Jon > >>>>>>> > >>>>>>> On Tue, Jun 8, 2021 at 9:02 AM Matthew Broadhead > >>>>>>> <[email protected]> wrote: > >>>>>>> > >>>>>>>> Hi Jon, > >>>>>>>> > >>>>>>>> NATS is basically a message queue, like ActiveMQ I suppose. > >>>>>>>> > >>>>>>>> I included the adapter into the project using maven > >>>>>>>> <dependency> > >>>>>>>> <groupId>io.nats</groupId> > >>>>>>>> <artifactId>java-nats-streaming</artifactId> > >>>>>>>> <version>2.2.3</version> > >>>>>>>> </dependency> > >>>>>>>> > >>>>>>>> i started up a nats server using docker. here is my > >>>>>> docker-compose.yml > >>>>>>>> version: '3.1' > >>>>>>>> services: > >>>>>>>> nats-docker: > >>>>>>>> image: nats-streaming:0.17.0 > >>>>>>>> restart: always > >>>>>>>> command: > >>>>>>>> - '-p' > >>>>>>>> - '4222' > >>>>>>>> - '-m' > >>>>>>>> - '8222' > >>>>>>>> - '-hbi' > >>>>>>>> - '5s' > >>>>>>>> - '-hbt' > >>>>>>>> - '5s' > >>>>>>>> - '-hbf' > >>>>>>>> - '2' > >>>>>>>> - '-SD' > >>>>>>>> - '-cid' > >>>>>>>> - 'yourclientid' > >>>>>>>> environment: > >>>>>>>> TZ: Europe/London > >>>>>>>> LANG: en_GB.UTF-8 > >>>>>>>> LANGUAGE: en_GB:en > >>>>>>>> LC_ALL: en_GB.UTF-8 > >>>>>>>> ports: > >>>>>>>> - '4222:4222' > >>>>>>>> - '8222:8222' > >>>>>>>> expose: > >>>>>>>> - 4222 > >>>>>>>> - 8222 > >>>>>>>> networks: > >>>>>>>> - backend > >>>>>>>> networks: > >>>>>>>> backend: > >>>>>>>> driver: bridge > >>>>>>>> > >>>>>>>> JCA sounds good if it solves the threading issue. it is very kind > >> of > >>>>>>>> you to offer to help write an adapter. looking at the code you > sent > >>>>>> it > >>>>>>>> looks complicated but i can have a stab at it if you don't have > much > >>>>>> time > >>>>>>>> let me know if you need more info > >>>>>>>> > >>>>>>>> Matthew > >>>>>>>> > >>>>>>>> On 07/06/2021 17:48, Jonathan Gallimore wrote: > >>>>>>>>> At the risk of sounding a bit ignorant... what is NATS? > >>>>>>>>> > >>>>>>>>> From what I can tell, it sounds like you're receiving a > stream > >> of > >>>>>> events > >>>>>>>>> (over websocket) and want to do some processing in an EJB or CDI > >>>>>> bean for > >>>>>>>>> each event. The connection to the NATS server isn't in the > context > >>>>>> of a > >>>>>>>>> HTTP (or any other type of) request, and just runs all the time > >>>>>> while the > >>>>>>>>> server is running - does that sound about right? > >>>>>>>>> > >>>>>>>>> Assuming that sounds right, it sounds a bit like the Slack JCA > >>>>>> connector > >>>>>>>> I > >>>>>>>>> wrote a while back: > >>>>>>>>> > >> https://github.com/apache/tomee-chatterbox/tree/master/chatterbox-slack > . > >>>>>>>>> Essentially, the resource adapter connects to slack and runs all > >> the > >>>>>>>> time. > >>>>>>>>> Messages that come into the server from slack are processed in > MDBs > >>>>>> that > >>>>>>>>> implement the InboundListener interface. > >>>>>>>>> > >>>>>>>>> JCA certainly feels complex, especially when compared with your > >>>>>>>>> Singleton @Startup bean approach, but I usually find that if I > try > >>>>>> and > >>>>>>>> work > >>>>>>>>> with threads in EJBs, things usually go in the wrong direction. > >>>>>>>> Conversely, > >>>>>>>>> JCA even gives you a work manager to potentially handle that > stuff. > >>>>>>>>> > >>>>>>>>> If you can give me some pointers to running a NATS server, I'd be > >>>>>> happy > >>>>>>>> to > >>>>>>>>> help with a sample adapter and application. > >>>>>>>>> > >>>>>>>>> Jon > >>>>>>>>> > >>>>>>>>> On Mon, Jun 7, 2021 at 11:49 AM Matthew Broadhead > >>>>>>>>> <[email protected]> wrote: > >>>>>>>>> > >>>>>>>>>> I am trying to subscribe to a NATS streaming server with > >>>>>>>>>> https://github.com/nats-io/stan.java which is > >>>>>> java.lang.Autocloseable. > >>>>>>>>>> At first it wasn't closing properly as seen in my original gist: > >>>>>>>>>> > https://gist.github.com/chongma/2a3ab451f2aeabc98340a9b897394cfe > >>>>>>>>>> > >>>>>>>>>> This was solved with this > >>>>>>>>>> > >>>>>>>>>> > >> > https://stackoverflow.com/questions/39080296/hazelcast-threads-prevent-tomee-from-stopping > >>>>>>>>>> creating a default producer: > >>>>>>>>>> @ApplicationScoped > >>>>>>>>>> public class NatsConnectionProducer { > >>>>>>>>>> > >>>>>>>>>> @Resource(name = "baseAddressNats") > >>>>>>>>>> private String baseAddressNats; > >>>>>>>>>> > >>>>>>>>>> @Produces > >>>>>>>>>> @ApplicationScoped > >>>>>>>>>> public StreamingConnection instance() throws > IOException, > >>>>>>>>>> InterruptedException { > >>>>>>>>>> StreamingConnectionFactory cf = new > >>>>>>>>>> StreamingConnectionFactory(new > >>>>>>>> Options.Builder().natsUrl(baseAddressNats) > >>>>>>>>>> .clusterId("cluster-id").clientId("client-id").build()); > >>>>>>>>>> return cf.createConnection(); > >>>>>>>>>> } > >>>>>>>>>> > >>>>>>>>>> public void destroy(@Disposes final StreamingConnection > >>>>>> instance) > >>>>>>>>>> throws IOException, TimeoutException, > >>>>>>>> InterruptedException { > >>>>>>>>>> instance.close(); > >>>>>>>>>> } > >>>>>>>>>> } > >>>>>>>>>> > >>>>>>>>>> But now i am creating a new thread because any injections with > JPA > >>>>>> had > >>>>>>>>>> cacheing issues and this seems to work but i am not sure it is > >>>>>>>>>> broadcasting to websockets correctly > >>>>>>>>>> @Singleton > >>>>>>>>>> @Lock(LockType.READ) > >>>>>>>>>> @Startup > >>>>>>>>>> public class SchedulerEvents { > >>>>>>>>>> private static final Logger log = > >>>>>>>>>> Logger.getLogger(SchedulerEvents.class.getName()); > >>>>>>>>>> > >>>>>>>>>> @Inject > >>>>>>>>>> private StreamingConnection streamingConnection; > >>>>>>>>>> > >>>>>>>>>> @Inject > >>>>>>>>>> private SomeController someController; > >>>>>>>>>> > >>>>>>>>>> @PostConstruct > >>>>>>>>>> private void construct() { > >>>>>>>>>> // log.fine(Thread.currentThread().getName()); > >>>>>>>>>> try { > >>>>>>>>>> > streamingConnection.subscribe("scheduler:notify", > >> new > >>>>>>>>>> MessageHandler() { > >>>>>>>>>> @Override > >>>>>>>>>> public void onMessage(Message m) { > >>>>>>>>>> try { > >>>>>>>>>> > >>>>>> log.fine(Thread.currentThread().getName()); > >>>>>>>>>> // this needs to spawn a new thread > >>>>>> otherwise > >>>>>>>>>> injections are stale > >>>>>>>>>> Thread thread = new Thread(new > >>>>>> Runnable() { > >>>>>>>>>> public void run() { > >>>>>>>>>> log.fine(Thread.currentThread().getName()); > >>>>>>>>>> process(m.getData()); > >>>>>>>>>> } > >>>>>>>>>> }); > >>>>>>>>>> thread.start(); > >>>>>>>>>> while (thread.isAlive()) { > >>>>>>>>>> // wait > >>>>>>>>>> } > >>>>>>>>>> log.fine("Thread finished OK"); > >>>>>>>>>> m.ack(); > >>>>>>>>>> } catch (Exception e) { > >>>>>>>>>> emailController.emailStackTrace(e); > >>>>>>>>>> } > >>>>>>>>>> } > >>>>>>>>>> }, new > >>>>>>>>>> > >>>>>>>>>> > >> > SubscriptionOptions.Builder().startWithLastReceived().manualAcks().ackWait(Duration.ofSeconds(60)) > >> .durableName("scheduler-service").build()); > >>>>>>>>>> } catch (IOException | InterruptedException | > >>>>>>>> TimeoutException e) > >>>>>>>>>> { > >>>>>>>>>> e.printStackTrace(); > >>>>>>>>>> } > >>>>>>>>>> } > >>>>>>>>>> > >>>>>>>>>> private void process(byte[] data) { > >>>>>>>>>> String raw = new String(data); > >>>>>>>>>> JsonReader jsonReader = Json.createReader(new > >>>>>>>> StringReader(raw)); > >>>>>>>>>> JsonObject jo = jsonReader.readObject(); > >>>>>>>>>> jsonReader.close(); > >>>>>>>>>> String type = utilityDao.readJsonString(jo, > "type"); > >>>>>>>>>> int id = utilityDao.readJsonInteger(jo, "id"); > >>>>>>>>>> if (type == null || id == 0) { > >>>>>>>>>> emailController.emailThrowable(new Throwable(), > >> raw); > >>>>>>>>>> return; > >>>>>>>>>> } > >>>>>>>>>> log.info("Received a message: id: " + id + ", > type:" > >> + > >>>>>> type); > >>>>>>>>>> DefaultServerEndpointConfigurator dsec = new > >>>>>>>>>> DefaultServerEndpointConfigurator(); > >>>>>>>>>> SomeWebSocket nws = > >>>>>>>> dsec.getEndpointInstance(SomeWebSocket.class); > >>>>>>>>>> nws.broadcast(ja.toString()); > >>>>>>>>>> } > >>>>>>>>>> > >>>>>>>>>> } > >>>>>>>>>> > >>>>>>>>>> what is the best way to use an autocloseable? > >>>>>>>>>> > >>>>>>>>>> > >> > >
