java: a refused listener subscription closes the connection it started (#7264)

[delchev]

Fixes #7264

ActiveMQConnectionArtifactsFactory.createConnection start()s the connection before returning it, so by the time createSession / createTopic / configureRedeliveryPolicy / createDurableSubscriber / setMessageListener can throw, a transport socket and its ActiveMQ thread exist. The catch in ListenerClassConsumer.subscribe reported the failure and returned null without closing them.

Before #7220 that ran once per rebuild, so the cost was one orphaned connection per refused subscription. Now JavaConsumersReconciler re-runs subscribe every 30 s for as long as the refusal lasts, and the realistic refusals at exactly this point are permanent: an external broker (DIRIGIBLE_MESSAGING_BROKER_URL) whose destination authorization refuses the consumer with a JMSSecurityException, or a destination name its policy rejects. One started connection per subscription per tenant per tick, at DEBUG after the first WARN — an outage the retry itself manufactures.

Change

• connection is held in a local declared before the try, and the catch calls a new closeQuietly(label, connection).
• The close failure is logged at DEBUG with the throwable: the refusal is already reported, and a broker that just refused the subscription is likely to refuse the close too, so it must not add a second line per tick to a lasting outage.

Tests

Three cases in ListenerClassConsumerRetryTest — none of the existing ones makes anything after createConnection throw, so the path was untested. The mock factory now hands out the connection and refuses the session with a JMSSecurityException, which is where a broker's destination authorization really says no:

• aRefusalAfterTheConnectionWasStartedClosesIt — nothing subscribed, and both tenants' connections closed.
• everyRetryOfALastingRefusalClosesItsOwnConnection — three passes close three per tenant; the retry accumulates nothing.
• theSubscriptionStillOpensAfterAClosedAttempt — closing an attempt is not recording it; the subscription opens once on the first pass the broker accepts.

mvn -pl components/engine/engine-java test -Dtest='ListenerClassConsumer*Test' → 24 tests, all green. formatter:validate and the release javadoc profile pass on the module.

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