title | description | ms.date | ms.topic | ms.devlang | ms.custom |
---|---|---|---|---|---|
Get started with Azure Service Bus queues (Java) |
This tutorial shows you how to send messages to and receive messages from Azure Service Bus queues using the Java programming language. |
02/28/2024 |
quickstart |
java |
passwordless-java, devx-track-extended-java |
[!div class="op_single_selector" title1="Select the programming language:"]
In this quickstart, you create a Java app to send messages to and receive messages from an Azure Service Bus queue.
Note
This quick start provides step-by-step instructions for a simple scenario of sending messages to a Service Bus queue and receiving them. You can find pre-built Java samples for Azure Service Bus in the Azure SDK for Java repository on GitHub.
Tip
If you're working with Azure Service Bus resources in a Spring application, we recommend that you consider Spring Cloud Azure as an alternative. Spring Cloud Azure is an open-source project that provides seamless Spring integration with Azure services. To learn more about Spring Cloud Azure, and to see an example using Service Bus, see Spring Cloud Stream with Azure Service Bus.
- An Azure subscription. To complete this tutorial, you need an Azure account. You can activate your MSDN subscriber benefits or sign up for a free account.
- Install Azure SDK for Java. If you're using Eclipse, you can install the Azure Toolkit for Eclipse that includes the Azure SDK for Java. You can then add the Microsoft Azure Libraries for Java to your project. If you're using IntelliJ, see Install the Azure Toolkit for IntelliJ.
[!INCLUDE service-bus-create-namespace-portal]
[!INCLUDE service-bus-create-queue-portal]
[!INCLUDE service-bus-passwordless-template-tabbed]
In this section, you'll create a Java console project, and add code to send messages to the queue that you created earlier.
Create a Java project using Eclipse or a tool of your choice.
Add references to Azure Core and Azure Service Bus libraries.
If you're using Eclipse and created a Java console application, convert your Java project to a Maven: right-click the project in the Package Explorer window, select Configure -> Convert to Maven project. Then, add dependencies to these two libraries as shown in the following example.
Update the pom.xml
file to add dependencies to Azure Service Bus and Azure Identity packages.
<dependencies>
<dependency>
<groupId>com.azure</groupId>
<artifactId>azure-messaging-servicebus</artifactId>
<version>7.13.3</version>
</dependency>
<dependency>
<groupId>com.azure</groupId>
<artifactId>azure-identity</artifactId>
<version>1.8.0</version>
<scope>compile</scope>
</dependency>
</dependencies>
Update the pom.xml
file to add a dependency to the Azure Service Bus package.
<dependency>
<groupId>com.azure</groupId>
<artifactId>azure-messaging-servicebus</artifactId>
<version>7.13.3</version>
</dependency>
-
Add the following
import
statements at the topic of the Java file.import com.azure.messaging.servicebus.*; import com.azure.identity.*; import java.util.concurrent.TimeUnit; import java.util.Arrays; import java.util.List;
import com.azure.messaging.servicebus.*; import java.util.concurrent.TimeUnit; import java.util.Arrays; import java.util.List;
-
In the class, define variables to hold connection string and queue name.
static String queueName = "<QUEUE NAME>";
[!IMPORTANT] Replace
<QUEUE NAME>
with the name of the queue.static String connectionString = "<NAMESPACE CONNECTION STRING>"; static String queueName = "<QUEUE NAME>";
[!IMPORTANT] Replace
<NAMESPACE CONNECTION STRING>
with the connection string to your Service Bus namespace, and<QUEUE NAME>
with the name of the queue.
-
Add a method named
sendMessage
in the class to send one message to the queue.[!IMPORTANT] Replace
NAMESPACENAME
with the name of your Service Bus namespace.static void sendMessage() { // create a token using the default Azure credential DefaultAzureCredential credential = new DefaultAzureCredentialBuilder() .build(); ServiceBusSenderClient senderClient = new ServiceBusClientBuilder() .fullyQualifiedNamespace("NAMESPACENAME.servicebus.windows.net") .credential(credential) .sender() .queueName(queueName) .buildClient(); // send one message to the queue senderClient.sendMessage(new ServiceBusMessage("Hello, World!")); System.out.println("Sent a single message to the queue: " + queueName); }
static void sendMessage() { // create a Service Bus Sender client for the queue ServiceBusSenderClient senderClient = new ServiceBusClientBuilder() .connectionString(connectionString) .sender() .queueName(queueName) .buildClient(); // send one message to the queue senderClient.sendMessage(new ServiceBusMessage("Hello, World!")); System.out.println("Sent a single message to the queue: " + queueName); }
-
Add a method named
createMessages
in the class to create a list of messages. Typically, you get these messages from different parts of your application. Here, we create a list of sample messages.static List<ServiceBusMessage> createMessages() { // create a list of messages and return it to the caller ServiceBusMessage[] messages = { new ServiceBusMessage("First message"), new ServiceBusMessage("Second message"), new ServiceBusMessage("Third message") }; return Arrays.asList(messages); }
-
Add a method named
sendMessageBatch
method to send messages to the queue you created. This method creates aServiceBusSenderClient
for the queue, invokes thecreateMessages
method to get the list of messages, prepares one or more batches, and sends the batches to the queue.[!IMPORTANT] Replace
NAMESPACENAME
with the name of your Service Bus namespace.static void sendMessageBatch() { // create a token using the default Azure credential DefaultAzureCredential credential = new DefaultAzureCredentialBuilder() .build(); ServiceBusSenderClient senderClient = new ServiceBusClientBuilder() .fullyQualifiedNamespace("NAMESPACENAME.servicebus.windows.net") .credential(credential) .sender() .queueName(queueName) .buildClient(); // Creates an ServiceBusMessageBatch where the ServiceBus. ServiceBusMessageBatch messageBatch = senderClient.createMessageBatch(); // create a list of messages List<ServiceBusMessage> listOfMessages = createMessages(); // We try to add as many messages as a batch can fit based on the maximum size and send to Service Bus when // the batch can hold no more messages. Create a new batch for next set of messages and repeat until all // messages are sent. for (ServiceBusMessage message : listOfMessages) { if (messageBatch.tryAddMessage(message)) { continue; } // The batch is full, so we create a new batch and send the batch. senderClient.sendMessages(messageBatch); System.out.println("Sent a batch of messages to the queue: " + queueName); // create a new batch messageBatch = senderClient.createMessageBatch(); // Add that message that we couldn't before. if (!messageBatch.tryAddMessage(message)) { System.err.printf("Message is too large for an empty batch. Skipping. Max size: %s.", messageBatch.getMaxSizeInBytes()); } } if (messageBatch.getCount() > 0) { senderClient.sendMessages(messageBatch); System.out.println("Sent a batch of messages to the queue: " + queueName); } //close the client senderClient.close(); }
static void sendMessageBatch() { // create a Service Bus Sender client for the queue ServiceBusSenderClient senderClient = new ServiceBusClientBuilder() .connectionString(connectionString) .sender() .queueName(queueName) .buildClient(); // Creates an ServiceBusMessageBatch where the ServiceBus. ServiceBusMessageBatch messageBatch = senderClient.createMessageBatch(); // create a list of messages List<ServiceBusMessage> listOfMessages = createMessages(); // We try to add as many messages as a batch can fit based on the maximum size and send to Service Bus when // the batch can hold no more messages. Create a new batch for next set of messages and repeat until all // messages are sent. for (ServiceBusMessage message : listOfMessages) { if (messageBatch.tryAddMessage(message)) { continue; } // The batch is full, so we create a new batch and send the batch. senderClient.sendMessages(messageBatch); System.out.println("Sent a batch of messages to the queue: " + queueName); // create a new batch messageBatch = senderClient.createMessageBatch(); // Add that message that we couldn't before. if (!messageBatch.tryAddMessage(message)) { System.err.printf("Message is too large for an empty batch. Skipping. Max size: %s.", messageBatch.getMaxSizeInBytes()); } } if (messageBatch.getCount() > 0) { senderClient.sendMessages(messageBatch); System.out.println("Sent a batch of messages to the queue: " + queueName); } //close the client senderClient.close(); }
In this section, you add code to retrieve messages from the queue.
-
Add a method named
receiveMessages
to receive messages from the queue. This method creates aServiceBusProcessorClient
for the queue by specifying a handler for processing messages and another one for handling errors. Then, it starts the processor, waits for few seconds, prints the messages that are received, and then stops and closes the processor.[!IMPORTANT]
- Replace
NAMESPACENAME
with the name of your Service Bus namespace. - Replace
QueueTest
inQueueTest::processMessage
in the code with the name of your class.
// handles received messages static void receiveMessages() throws InterruptedException { DefaultAzureCredential credential = new DefaultAzureCredentialBuilder() .build(); ServiceBusProcessorClient processorClient = new ServiceBusClientBuilder() .fullyQualifiedNamespace("NAMESPACENAME.servicebus.windows.net") .credential(credential) .processor() .queueName(queueName) .processMessage(context -> processMessage(context)) .processError(context -> processError(context)) .buildProcessorClient(); System.out.println("Starting the processor"); processorClient.start(); TimeUnit.SECONDS.sleep(10); System.out.println("Stopping and closing the processor"); processorClient.close(); }
[!IMPORTANT] Replace
QueueTest
inQueueTest::processMessage
in the code with the name of your class.// handles received messages static void receiveMessages() throws InterruptedException { // Create an instance of the processor through the ServiceBusClientBuilder ServiceBusProcessorClient processorClient = new ServiceBusClientBuilder() .connectionString(connectionString) .processor() .queueName(queueName) .processMessage(QueueTest::processMessage) .processError(context -> processError(context)) .buildProcessorClient(); System.out.println("Starting the processor"); processorClient.start(); TimeUnit.SECONDS.sleep(10); System.out.println("Stopping and closing the processor"); processorClient.close(); }
- Replace
-
Add the
processMessage
method to process a message received from the Service Bus subscription.private static void processMessage(ServiceBusReceivedMessageContext context) { ServiceBusReceivedMessage message = context.getMessage(); System.out.printf("Processing message. Session: %s, Sequence #: %s. Contents: %s%n", message.getMessageId(), message.getSequenceNumber(), message.getBody()); }
-
Add the
processError
method to handle error messages.private static void processError(ServiceBusErrorContext context) { System.out.printf("Error when receiving messages from namespace: '%s'. Entity: '%s'%n", context.getFullyQualifiedNamespace(), context.getEntityPath()); if (!(context.getException() instanceof ServiceBusException)) { System.out.printf("Non-ServiceBusException occurred: %s%n", context.getException()); return; } ServiceBusException exception = (ServiceBusException) context.getException(); ServiceBusFailureReason reason = exception.getReason(); if (reason == ServiceBusFailureReason.MESSAGING_ENTITY_DISABLED || reason == ServiceBusFailureReason.MESSAGING_ENTITY_NOT_FOUND || reason == ServiceBusFailureReason.UNAUTHORIZED) { System.out.printf("An unrecoverable error occurred. Stopping processing with reason %s: %s%n", reason, exception.getMessage()); } else if (reason == ServiceBusFailureReason.MESSAGE_LOCK_LOST) { System.out.printf("Message lock lost for message: %s%n", context.getException()); } else if (reason == ServiceBusFailureReason.SERVICE_BUSY) { try { // Choosing an arbitrary amount of time to wait until trying again. TimeUnit.SECONDS.sleep(1); } catch (InterruptedException e) { System.err.println("Unable to sleep for period of time"); } } else { System.out.printf("Error source %s, reason %s, message: %s%n", context.getErrorSource(), reason, context.getException()); } }
-
Update the
main
method to invokesendMessage
,sendMessageBatch
, andreceiveMessages
methods and to throwInterruptedException
.public static void main(String[] args) throws InterruptedException { sendMessage(); sendMessageBatch(); receiveMessages(); }
-
If you're using Eclipse, right-click the project, select Export, expand Java, select Runnable JAR file, and follow the steps to create a runnable JAR file.
-
If you're signed into the machine using a user account that's different from the user account added to the Azure Service Bus Data Owner role, follow these steps. Otherwise, skip this step and move on to run the Jar file in the next step.
-
Install Azure CLI on your machine.
-
Run the following CLI command to sign in to Azure. Use the same user account that you added to the Azure Service Bus Data Owner role.
az login
-
-
Run the Jar file using the following command.
java -jar <JAR FILE NAME>
-
You see the following output in the console window.
Sent a single message to the queue: myqueue Sent a batch of messages to the queue: myqueue Starting the processor Processing message. Session: 88d961dd801f449e9c3e0f8a5393a527, Sequence #: 1. Contents: Hello, World! Processing message. Session: e90c8d9039ce403bbe1d0ec7038033a0, Sequence #: 2. Contents: First message Processing message. Session: 311a216a560c47d184f9831984e6ac1d, Sequence #: 3. Contents: Second message Processing message. Session: f9a871be07414baf9505f2c3d466c4ab, Sequence #: 4. Contents: Third message Stopping and closing the processor
When you run the application, you see the following messages in the console window.
Sent a single message to the queue: myqueue
Sent a batch of messages to the queue: myqueue
Starting the processor
Processing message. Session: 88d961dd801f449e9c3e0f8a5393a527, Sequence #: 1. Contents: Hello, World!
Processing message. Session: e90c8d9039ce403bbe1d0ec7038033a0, Sequence #: 2. Contents: First message
Processing message. Session: 311a216a560c47d184f9831984e6ac1d, Sequence #: 3. Contents: Second message
Processing message. Session: f9a871be07414baf9505f2c3d466c4ab, Sequence #: 4. Contents: Third message
Stopping and closing the processor
On the Overview page for the Service Bus namespace in the Azure portal, you can see incoming and outgoing message count. Wait for a minute or so and then refresh the page to see the latest values.
:::image type="content" source="./media/service-bus-java-how-to-use-queues/overview-incoming-outgoing-messages.png" alt-text="Incoming and outgoing message count" lightbox="./media/service-bus-java-how-to-use-queues/overview-incoming-outgoing-messages.png":::
Select the queue on this Overview page to navigate to the Service Bus Queue page. You see the incoming and outgoing message count on this page too. You also see other information such as the current size of the queue, maximum size, active message count, and so on.
:::image type="content" source="./media/service-bus-java-how-to-use-queues/queue-details.png" alt-text="Queue details" lightbox="./media/service-bus-java-how-to-use-queues/queue-details.png":::
See the following documentation and samples: