feat(azure-servicebus): Ensure Content-Type header is propagated into AMQP Message.

[fernandobalieiro]

Description

The goal of this PR is to ensure that when Content-Type header is present, it's properly propagated into the Content-Type field of the raw AMQP Message.

Motivation

SmallRye Reactive Messaging relies on the raw AQMP Content-Type to determine whether it should or not convert the payload into a io.vertx.core.json.JsonObject:

        if (body instanceof Data) {
            Binary bin = ((Data) body).getValue();
            byte[] bytes = new byte[bin.getLength()];
            System.arraycopy(bin.getArray(), bin.getArrayOffset(), bytes, 0, bin.getLength());

            if (APPLICATION_JSON.equalsIgnoreCase(msg.contentType())) {
                return Buffer.buffer(bytes).toJson();
            }
            return bytes;
        }

If the Content-Type application/json is not present, the conversion does not happen, and methods annotated with @Incoming with a JsonObject as parameter (such as the one below) break.

In a scenario where Azure Service Bus Producers are migrated to use Apache Camel, all the Consumers that are relying on SmallRye Reactive Messaging will break.

Example method:

    @Incoming("my-subscription")
    public Uni<Void> handleMessage(final JsonObject messageJson) {
        return Uni.createFrom().item(messageJson)
            .call(() -> handle(messageJson))
            .replaceWithVoid();
    }

Stack Trace when consuming the message:

2025-10-22 12:24:34.665 ERROR io.sm.re.me.pr.AbstractMediator:166 [vert.x-eventloop-thread-5-215] SRMSG00200: The method com.acme.MyEventHandler#handleMessage has thrown an exception: java.lang.ClassCastException: class [B cannot be cast to class io.vertx.core.json.JsonObject ([B is in module java.base of loader 'bootstrap'; io.vertx.core.json.JsonObject is in unnamed module of loader io.quarkus.bootstrap.classloading.QuarkusClassLoader @4f83df68)
        at com.acme.MyEventHandler_SmallRyeMessagingInvoker_handleMessage_23d540434dcfaa61d3f6031df6da3d9e581a58aa.invoke(Unknown Source)
        at io.smallrye.reactive.messaging.providers.AbstractMediator.invoke(AbstractMediator.java:164)
        at io.smallrye.reactive.messaging.providers.AbstractMediator.lambda$invokeOnMessageContext$13(AbstractMediator.java:172)
        at io.smallrye.reactive.messaging.providers.locals.LocalContextMetadata.lambda$invokeOnMessageContext$0(LocalContextMetadata.java:34)
        at io.smallrye.reactive.messaging.providers.locals.LocalContextMetadata.lambda$invokeOnMessageContext$1(LocalContextMetadata.java:53)
        at io.smallrye.reactive.messaging.providers.helpers.VertxContext.runOnContext(VertxContext.java:33)
        at io.smallrye.reactive.messaging.providers.locals.LocalContextMetadata.lambda$invokeOnMessageContext$2(LocalContextMetadata.java:51)
        at io.smallrye.context.impl.wrappers.SlowContextualConsumer.accept(SlowContextualConsumer.java:21)
        at io.smallrye.mutiny.operators.uni.builders.UniCreateWithEmitter.subscribe(UniCreateWithEmitter.java:22)
        at io.smallrye.mutiny.operators.AbstractUni.subscribe(AbstractUni.java:35)
        at io.smallrye.mutiny.operators.uni.UniOnItemTransformToUni.subscribe(UniOnItemTransformToUni.java:25)
        at io.smallrye.mutiny.operators.AbstractUni.subscribe(AbstractUni.java:35)
        at io.smallrye.mutiny.operators.uni.UniOnItemOrFailureFlatMap.subscribe(UniOnItemOrFailureFlatMap.java:27)
        at io.smallrye.mutiny.operators.AbstractUni.subscribe(AbstractUni.java:35)
        at io.smallrye.mutiny.converters.uni.UniToMultiPublisher$UniToMultiSubscription.request(UniToMultiPublisher.java:74)
        at io.smallrye.mutiny.operators.multi.MultiConcatMapOp$MainSubscriber.innerOnSubscribe(MultiConcatMapOp.java:109)
        at io.smallrye.mutiny.operators.multi.MultiConcatMapOp$MainSubscriber$InnerSubscriber.onSubscribe(MultiConcatMapOp.java:297)
        at io.smallrye.mutiny.converters.uni.UniToMultiPublisher.subscribe(UniToMultiPublisher.java:25)
        at io.smallrye.mutiny.groups.MultiCreate$1.subscribe(MultiCreate.java:165)
        at io.smallrye.mutiny.operators.multi.MultiConcatMapOp$MainSubscriber.onItem(MultiConcatMapOp.java:119)
        at io.smallrye.mutiny.operators.multi.MultiMapOp$MapProcessor.onItem(MultiMapOp.java:50)
        at io.smallrye.mutiny.operators.multi.MultiOnItemInvoke$MultiOnItemInvokeProcessor.onItem(MultiOnItemInvoke.java:41)
        at io.smallrye.mutiny.operators.multi.MultiOperatorProcessor.onItem(MultiOperatorProcessor.java:100)
        at io.smallrye.reactive.messaging.providers.locals.ContextOperator$ContextMulti$ContextProcessor.lambda$onItem$1(ContextOperator.java:71)
        at io.smallrye.reactive.messaging.providers.helpers.VertxContext.lambda$runOnContext$0(VertxContext.java:35)
        at io.vertx.core.impl.ContextInternal.dispatch(ContextInternal.java:270)
        at io.vertx.core.impl.ContextInternal.dispatch(ContextInternal.java:252)
        at io.vertx.core.impl.ContextInternal.lambda$runOnContext$0(ContextInternal.java:50)
        at io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:173)
        at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:166)
        at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:472)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:569)
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:998)
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
        at java.base/java.lang.Thread.run(Thread.java:1583)

Target

• I checked that the commit is targeting the correct branch (Camel 4 uses the main branch)

Tracking

• If this is a large change, bug fix, or code improvement, I checked there is a JIRA issue filed for the change (usually before you start working on it).

Apache Camel coding standards and style

• I checked that each commit in the pull request has a meaningful subject line and body.

• I have run mvn clean install -DskipTests locally from root folder and I have committed all auto-generated changes.

[github-actions]

🌟 Thank you for your contribution to the Apache Camel project! 🌟

🤖 CI automation will test this PR automatically.

🐫 Apache Camel Committers, please review the following items:

• First-time contributors require MANUAL approval for the GitHub Actions to run

• You can use the command /component-test (camel-)component-name1 (camel-)component-name2.. to request a test from the test bot.

• You can label PRs using build-all, build-dependents, skip-tests and test-dependents to fine-tune the checks executed by this PR.

• Build and test logs are available in the Summary page. Only Apache Camel committers have access to the summary.

• ⚠️ Be careful when sharing logs. Review their contents before sharing them publicly.

[apupier]

/component-test azure

Result ✅ The tests passed successfully

[github-actions]

🤖 The Apache Camel test robot will run the tests for you 👍

[davsclaus]

Thanks for the PR.

[fernandobalieiro]

Thanks for the PR.

Thank you for the quick review, @davsclaus and @oscerd.
Do you have an ETA on when the new version with this would be released?

Regards.

[davsclaus]

Sometime next month