FTL Client API

The samples provided use our FTL API to send messages. We will show an example of our API being used to send a message on a queue.

info

These snippets skip full production error handling and closing. Use best practices when creating applications.

Go

Subscriber

We first connect to the FTL server and set up our message channel, event queue, and the subscriber on the quickstart queue destination:

realm, _ := ftl.Connect("http://localhost:8585", "", nil)
messageChannel := make(chan ftl.Message)
queue, _ := realm.NewQueue(nil, nil)
sub, _ := queue.SubscribeOnDest("Q:quickstart.queue", nil, messageChannel)

We then wait for the message on our message channel and print its contents upon obtaining it:

msg := <-messageChannel
fmt.Printf("received message: %s\n", msg.String())

Publisher

We first connect to the FTL server and make a new destination publisher:

realm, _ := ftl.Connect("http://localhost:8585", "", nil)
pub, _ := realm.NewDestPublisher("", nil)

Then, we create a new message and set its type and message content:

msg, _ := realm.NewMessage("")
content := make(map[string]interface{})
content["type"] = "hello"
content["message"] = "hello world earth"

Lastly, we attach the content to the message and send it on our quickstart queue destination:

msg.Marshal(&content)
pub.Send("Q:quickstart.queue", msg)

Java

Subscriber

We first connect to the FTL server and set up our event queue:

Realm realm = FTL.connectToRealmServer("http://localhost:8585", null, null);
EventQueue queue = realm.createEventQueue();

We then set up our subscriber on the quickstart queue destination using the quickstart durable:

DestSubscriber sub = realm.createDestSubscriber("Q:quickstart.queue", null);

We then add the subcriber to our event queue and attach an implementation of the SubscriberListener interface that prints the message contents upon obtaining it:

public class SubListen implements SubscriberListener {
    public void messagesReceived(List<Message> messages, EventQueue eventQueue) {
        for (message : messages) {
            System.out.print("Received message");
            System.out.println(message.toString());
        }
    }
}

SubListen subListener = new SubListen();
queue.addDestSubscriber(sub, subListener);
queue.dispatch();

Publisher

We first connect to the FTL server and make a new destination publisher:

Realm realm = FTL.connectToRealmServer("http://localhost:8585", null, null);
DestPublisher pub = realm.createDestPublisher(null, null);

Then, we create a new message and set its type and message content:

Message msg = realm.createMessage("");
msg.setString("type", "hello");
msg.setString("message", "hello world earth");

Lastly, we send the message on our quickstart queue destination:

pub.send("Q:quickstart.queue", msg);

C

Subscriber

We first connect to the FTL server and set up our message channel and our event queue:

tibEx ex = tibEx_Create();
tibRealm realm = tibRealm_Connect(ex, "http://localhost:8585", NULL, NULL);
tibEventQueue queue = tibEventQueue_Create(ex, realm, NULL);

We then set up our subscriber on the quickstart queue destination using the quickstart durable:

tibDestSubscriber sub = tibRealm_CreateDestSubscriber(ex, realm, "Q:quickstart.queue", NULL);

We then add the subcriber to our event queue and attach an onMessages function that prints the message contents upon obtaining it:

void
onMessages(
    tibEx                       ex,
    tibEventQueue               msgQueue,
    tibint32_t                  msgNum,
    tibMessage*                 msgs,
    void**                      closures)
{
    char       buffer[1024];
    (void)tibMessage_ToString(ex, msgs[0], buffer, sizeof(buffer));
    printf("received message: %s\n", buffer);
}
tibEventQueue_AddDestSubscriber(ex, queue, sub, onMessages, NULL);
tibEventQueue_Dispatch(ex, queue, TIB_TIMEOUT_WAIT_FOREVER);

Publisher

We first connect to the FTL server and make a new destination publisher:

tibEx ex = tibEx_Create();
tibRealm realm = tibRealm_Connect(ex, "http://localhost:8585", NULL, NULL);
tibDestPublisher pub = tibRealm_CreateDestPublisher(ex, realm, NULL, NULL);

Then, we create a new message and set its type and message content:

tibMessage msg = tibMessage_Create(ex, realm, "");
tibMessage_SetString(ex, msg, "type", "hello");
tibMessage_SetString(ex, msg, "message", "hello world earth");

Lastly, we send the message on our quickstart queue destination:

tibDestPublisher_Send(ex, pub, "Q:quickstart.queue", msg);