Java – Unable to receive messages from Azure Service Bus Queue

I am new to working with Azure and I am trying to retrieve some messages from the Azure Service Bus queue that was set up by a client, but nothing happens when I run the code. It just waits for the timeout to complete and then stops–no errors and/or exceptions.

In addition to that, I stumbled upon the peekMessages() function and was able to successfully retrieve the messages.

The connection string and queue name are both valid. And as per client, they already had the "Listen" permission set up as well.

This is what I have done so far:

AzureServiceBusQueue queue = new AzureServiceBusQueue(MSCConstants.AZURE_UAT_CONNECTION_STRING, MSCConstants.AZURE_UAT_QUEUE_MAME);
queue.receiveMessages();

public void receiveMessages() throws Exception {
    AtomicBoolean sampleSuccessful = new AtomicBoolean(true);
    CountDownLatch countdownLatch = new CountDownLatch(1);

    try {
        ServiceBusReceiverAsyncClient receiver = new ServiceBusClientBuilder()
                .connectionString(connectionString)
                .receiver()
                .queueName(queueName)
                .maxAutoLockRenewDuration(Duration.ofMinutes(1))
                .disableAutoComplete()
                .buildAsyncClient();

        Disposable subscription = receiver.receiveMessages()
                .subscribe(message -> {
                            System.out.printf("Sequence #: %s. Contents: %s%n", message.getSequenceNumber(),
                                    message.getBody());
                        },
                        error -> {
                            System.err.println("Error occurred while receiving message: " + error);
                            sampleSuccessful.set(false);
                        });


        countdownLatch.await(60, TimeUnit.SECONDS);
        subscription.dispose();
        receiver.close();
    } catch (Exception ex) {
        ex.printStackTrace();
        throw ex;
    }
}

And when I ran this code, the program just waits for 60 seconds and then it stops. No errors, exceptions, or any log messages in the console.

Do you have any ideas/suggestions on what’s happening and what to do?

UPDATE:

I have also tried the approach below.

When I tried executing the code, it first prints "Testing." Then it waits for a couple of minutes before printing "123" next. The printing of the message details in between is never executed.

public void receiveMessagesV2() throws Exception {
        ServiceBusReceiverAsyncClient receiver = null;
        try {
            receiver = new ServiceBusClientBuilder()
                    .connectionString(getConnectionString())
                    .receiver()
                    .queueName(getQueueName())
                    .receiveMode(ServiceBusReceiveMode.PEEK_LOCK)
                    .disableAutoComplete()
                    .buildAsyncClient();

            for (int i = 0; i < 3; i++) {
                System.out.println("Testing");
                ServiceBusReceiverAsyncClient finalReceiver = receiver;
                receiver.receiveMessages().subscribe(message -> {
                    System.out.printf("Sequence #: %s. Contents: %s%n", message.getSequenceNumber(), message.getBody());

                    // Messages from the sync receiver MUST be settled explicitly.
                    finalReceiver.complete(message);
                });
                System.out.println("123");
            }
        } catch (Exception ex) {
            ex.printStackTrace();
            throw ex;
        } finally {
             receiver.close();
        }
    }