activemq

Apache ActiveMQ Classic connector for Aussom. One module covers both modes: an embedded broker running inside your JVM (entirely in memory or persisting to disk) and connections to an outside ActiveMQ server. The broker URL decides which one you get.

Built on ActiveMQ Classic 6.2.x (Jakarta JMS).

Classes

include activemq.activemq; pulls in everything; individual files can be included instead (for example include activemq.broker;).

Quick start: embedded, in memory

include activemq.activemq;

broker = new ActiveMqBroker("mybroker");
broker.start();

con = new ActiveMqConnection(broker.getVmUrl());
con.connect();
sess = con.createSession();

q = sess.createQueue("orders");
prod = sess.createProducer(q);
prod.send(sess.createTextMessage("hello"));

cons = sess.createConsumer(q);
m = cons.receive(5000);
c.println(m.getText());    // hello

con.close();
broker.stop();

Embedded with disk persistence

The data directory must live inside the app's app_data directory. Under Aussom Server the path is resolved and checked by the server's file rules; messages sent with the (default) persistent delivery mode survive a broker restart.

broker = new ActiveMqBroker("mybroker");
broker.setPersistent(true);
broker.setDataDirectory("app_data/activemq");
broker.start();

Connecting to an outside ActiveMQ server

con = new ActiveMqConnection("failover:(tcp://mq1:61616,tcp://mq2:61616)", "user", "pass");
con.connect();

An embedded broker can also accept outside clients:

broker.addConnector("tcp://0.0.0.0:61616");   // before start()

Feature notes

• Ack modes: auto (default), client, dups_ok, and ActiveMQ's individual via createSession(false, "client") etc. Transacted sessions via createSession(true) with commit() / rollback().
• Durable topic subscriptions: set a client ID on the connection first (setClientId), then createDurableSubscriber(topic, name).
• Request/reply: createTemporaryQueue() + setReplyTo + setCorrelationId; the service side replies with an anonymous producer's sendTo(msg.getReplyTo(), reply).
• Scheduled delivery: enable setSchedulerSupport(true) on the broker, then msg.setScheduledDelay(ms) (or period/repeat/cron).
• Object messages: deserialization is off by default. Allowlist packages with con.setTrustedPackages(["java.lang", "java.util"]) before connecting.
• Wildcards / composite destinations: ActiveMQ names like orders.> or a,b are plain strings and work unchanged.

Building and testing

mvn clean package

Tests are fully self-contained: the aunit suite (activemq-test.aus) runs against an embedded in-memory broker, including a real TCP round trip through a connector on a free port and a KahaDB persistence-across-restart check (written under ./app_data/, which is gitignored).

Aussom Server

The module ships its Java connector in a bundled JAR (aussom-activemq.jar). On first include, the module's loader calls app.loadJar("activemq/aussom-activemq.jar") to put it on the classpath. Aussom Server blocks dynamic JAR loading by default, so the server's security manager must allow it or the app fails at startup with one of these errors:

app.loadJar(): Security manager property 'aussom.app.loadjar' is false; dynamic jar loading is disabled on this server.
app.loadJar(): jar 'aussom-activemq.jar' is not permitted. ...

Add a securityManager block to the server section of config.yaml that turns loading on and allowlists this module's JAR:

local:
  server:
    # ...

    # Allow the activemq apac module to load its bundled
    # connector JAR with app.loadJar.
    securityManager:
      - "aussom.app.loadjar": true
      - "aussom.app.loadJarsAllowed": [
        "aussom-activemq.jar"
      ]

Setting "aussom.app.loadAllJars": true instead of the allowlist also works, but naming just the JARs you expect is the safer configuration. No security manager changes are needed when running under the plain Aussom CLI.

Server listener

Under Aussom Server, ActiveMqListener is the push-consumption path. Register it and the server runtime owns its lifecycle: a dedicated thread, reload/shutdown handling, and the auto-restart policy from applications.yaml (keyed by the listener name).

include app;
include activemq.activemq;

class orders : AppBase {
    private broker = null;

    public orders() {
        this.broker = new ActiveMqBroker("orders");
        this.broker.setPersistent(true);
        this.broker.setDataDirectory("app_data/activemq");
        this.broker.start();

        lst = new ActiveMqListener("orders.created");
        lst.setBrokerUrl(this.broker.getVmUrl());
        lst.setQueue("orders.created");
        lst.setAckMode("individual");
        lst.setOnMessage(::onOrder);
        app.registerListener(lst);
    }

    public onOrder(object Msg) {
        console.info("got order: " + Msg.getText());
        Msg.ack();
    }
}

Handlers run on the listener thread, so slow handlers apply natural back-pressure. A handler error never kills the receive loop: with client/individual/transacted ack modes the message is redelivered by default (setRedeliverOnError(false) to ack anyway), and an optional setOnError callback receives the error text. Outside the server (plain CLI, tests) the loop can be driven directly: startListener() blocks (run it on a Thread), stopListener() ends it.