mn create-app example.micronaut.micronautguide \
--features=jms-sqs,localstack,awaitility \
--build=maven \
--lang=java \
--test=junit
Table of Contents
- 1. Getting Started
- 2. What you will need
- 3. Solution
- 4. Writing the Application
- 5. Create an application
- 6. Testing
- 7. Amazon Web Services (AWS)
- 8. Creating a queue instance in Amazon Simple Queue Service (Amazon SQS)
- 9. Running the Application
- 10. Generate a Micronaut Application Native Executable with GraalVM
- 11. Next steps
- 12. License
Connect a Micronaut JMS Application to an AWS SQS Queue
Learn how to connect JMS Application to an AWS SQS Queue
Authors: Slavko Bodvanski
Micronaut Version: 4.6.3
1. Getting Started
In this guide, we will create a Micronaut application written in Java.
2. What you will need
To complete this guide, you will need the following:
-
Some time on your hands
-
A decent text editor or IDE (e.g. IntelliJ IDEA)
-
JDK 17 or greater installed with
JAVA_HOME
configured appropriately -
An AWS account with:
-
An IAM user with enough permissions to create and manage a queue instances in SQS.
-
The AWS CLI configured to use the IAM user above.
-
3. Solution
We recommend that you follow the instructions in the next sections and create the application step by step. However, you can go right to the completed example.
-
Download and unzip the source
4. Writing the Application
Create an application using the Micronaut Command Line Interface or with Micronaut Launch.
If you don’t specify the --build argument, Gradle with the Kotlin DSL is used as the build tool. If you don’t specify the --lang argument, Java is used as the language.If you don’t specify the --test argument, JUnit is used for Java and Kotlin, and Spock is used for Groovy.
|
The previous command creates a Micronaut application with the default package example.micronaut
in a directory named micronautguide
.
If you use Micronaut Launch, select Micronaut Application as application type and add jms-sqs
, localstack
, and awaitility
features.
If you have an existing Micronaut application and want to add the functionality described here, you can view the dependency and configuration changes from the specified features, and apply those changes to your application. |
5. Create an application
Let’s create a set of components that will use the Micronaut JMS to send and receive messages from AWS SQS
Amazon SQS is a reliable, highly-scalable hosted queue for storing messages as they travel between applications or microservices. Amazon SQS moves data between distributed application components and helps you decouple these components.
5.1. Configuration
Enable JMS SQS integration:
micronaut.jms.sqs.enabled=true
5.2. Creating a JMS Producer
Create a JMS Producer interface.
package example.micronaut;
import io.micronaut.jms.annotations.JMSProducer;
import io.micronaut.jms.annotations.Queue;
import io.micronaut.messaging.annotation.MessageBody;
import static io.micronaut.jms.sqs.configuration.SqsConfiguration.CONNECTION_FACTORY_BEAN_NAME;
@JMSProducer(CONNECTION_FACTORY_BEAN_NAME) (1)
public interface DemoProducer {
@Queue("demo_queue") (2)
void send(@MessageBody String body); (3)
}
1 | The JMSProducer annotation defines this interface as a client that sends messages. |
2 | The @Queue annotation indicates which queue the message should be published to. |
3 | The send method accepts a single parameter which is the payload of a message. |
5.3. Creating a JMS Consumer
Create a JMS Consumer class.
package example.micronaut;
import io.micronaut.jms.annotations.JMSListener;
import io.micronaut.jms.annotations.Queue;
import io.micronaut.messaging.annotation.MessageBody;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.concurrent.atomic.AtomicInteger;
import static io.micronaut.jms.sqs.configuration.SqsConfiguration.CONNECTION_FACTORY_BEAN_NAME;
@JMSListener(CONNECTION_FACTORY_BEAN_NAME) (1)
public class DemoConsumer {
private static final Logger LOG = LoggerFactory.getLogger(DemoConsumer.class);
private final AtomicInteger messageCount = new AtomicInteger(0);
@Queue(value = "demo_queue") (2)
public void receive(@MessageBody String body) { (3)
LOG.info("Message has been consumed. Message body: {}", body);
messageCount.incrementAndGet();
}
int getMessageCount() {
return messageCount.intValue();
}
}
1 | The @JMSListener defines the bean as a message listener. |
2 | The @Queue annotation indicates which queue to subscribe to. |
3 | The receive method accepts a single parameter which is the payload of a message. |
5.4. Creating a Controller
Let’s create a Controller with an endpoint that we will call to verify that message has been sent by the JMS Producer (DemoProducer
) and then finally received and consumed by the JMS Consumer (DemoConsumer
).
package example.micronaut;
import io.micronaut.http.HttpStatus;
import io.micronaut.http.annotation.Controller;
import io.micronaut.http.annotation.Post;
import io.micronaut.http.annotation.Status;
@Controller (1)
public class DemoController {
private final DemoProducer demoProducer;
public DemoController(DemoProducer demoProducer) { (2)
this.demoProducer = demoProducer;
}
@Post("/demo") (3)
@Status(HttpStatus.NO_CONTENT)
public void publishDemoMessages() {
demoProducer.send("Demo message body"); (4)
}
}
1 | The class is defined as a controller with the @Controller annotation mapped to the path / . |
2 | Use constructor injection to inject a bean of type DemoProducer . |
3 | Maps a GET request to /demo path, which attempts to publish a message to a SQS queue instance. |
4 | Calls send method on DemoProducer instances providing the message payload. |
6. Testing
To test, we will use LocalStack.
Develop and test your AWS applications locally to reduce development time and increase product velocity. Reduce unnecessary AWS spend and remove the complexity and risk of maintaining AWS dev accounts.
6.1. LocalStack Dependencies
Add the following dependencies to your test classpath:
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>junit-jupiter</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>localstack</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>testcontainers</artifactId>
<scope>test</scope>
</dependency>
First, we create a configuration properties object to encapsulate the configuration of the SQS client, which we will provide via LocalStack.
package example.micronaut;
import io.micronaut.context.annotation.ConfigurationBuilder;
import io.micronaut.context.annotation.ConfigurationProperties;
@ConfigurationProperties("aws") (1)
public class SqsConfig {
private String accessKeyId;
private String secretKey;
private String region;
@ConfigurationBuilder(configurationPrefix = "services.sqs")
final Sqs sqs = new Sqs();
public String getAccessKeyId() {
return accessKeyId;
}
public void setAccessKeyId(String accessKeyId) {
this.accessKeyId = accessKeyId;
}
public String getSecretKey() {
return secretKey;
}
public void setSecretKey(String secretKey) {
this.secretKey = secretKey;
}
public String getRegion() {
return region;
}
public void setRegion(String region) {
this.region = region;
}
public Sqs getSqs() {
return sqs;
}
public static class Sqs {
private String endpointOverride;
public String getEndpointOverride() {
return endpointOverride;
}
public void setEndpointOverride(String endpointOverride) {
this.endpointOverride = endpointOverride;
}
}
}
1 | The @ConfigurationProperties annotation takes the configuration prefix. |
Create a BeanCreatedEventListener
to override the SQS client endpoint with the LocalStack endpoint.
package example.micronaut;
import io.micronaut.context.event.BeanCreatedEvent;
import io.micronaut.context.event.BeanCreatedEventListener;
import io.micronaut.core.annotation.NonNull;
import jakarta.inject.Singleton;
import software.amazon.awssdk.auth.credentials.AwsBasicCredentials;
import software.amazon.awssdk.auth.credentials.StaticCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.sqs.SqsClientBuilder;
import java.net.URI;
import java.net.URISyntaxException;
@Singleton (1)
class SqsClientBuilderListener implements BeanCreatedEventListener<SqsClientBuilder> { (2)
private final SqsConfig sqsConfig;
SqsClientBuilderListener(SqsConfig sqsConfig) { (3)
this.sqsConfig = sqsConfig;
}
@Override
public SqsClientBuilder onCreated(@NonNull BeanCreatedEvent<SqsClientBuilder> event) {
SqsClientBuilder builder = event.getBean();
try {
return builder
.endpointOverride(new URI(sqsConfig.getSqs().getEndpointOverride()))
.credentialsProvider(
StaticCredentialsProvider.create(
AwsBasicCredentials.create(sqsConfig.getAccessKeyId(), sqsConfig.getSecretKey())
)
)
.region(Region.of(sqsConfig.getRegion()));
} catch (URISyntaxException e) {
throw new RuntimeException(e);
}
}
}
1 | Use jakarta.inject.Singleton to designate a class as a singleton. |
2 | Creating a @Singleton that implements BeanCreatedEventListener allows you to provide extra configuration to beans after creation. |
3 | Use constructor injection to inject a bean of type SqsConfig . |
Create a BeanCreatedEventListener
to create a SQS queue named demo_queue
.
package example.micronaut;
import io.micronaut.context.event.BeanCreatedEvent;
import io.micronaut.context.event.BeanCreatedEventListener;
import jakarta.inject.Singleton;
import software.amazon.awssdk.services.sqs.SqsClient;
import software.amazon.awssdk.services.sqs.model.CreateQueueRequest;
@Singleton (1)
public class SqsClientCreatedEventListener implements BeanCreatedEventListener<SqsClient> { (2)
private static final String QUEUE_NAME = "demo_queue";
@Override
public SqsClient onCreated(BeanCreatedEvent<SqsClient> event) {
SqsClient client = event.getBean();
if (client.listQueues().queueUrls().stream().noneMatch(it -> it.contains(QUEUE_NAME))) {
client.createQueue(
CreateQueueRequest.builder()
.queueName(QUEUE_NAME)
.build()
);
}
return client;
}
}
1 | Use jakarta.inject.Singleton to designate a class as a singleton. |
2 | Creating a @Singleton that implements BeanCreatedEventListener allows you to provide extra configuration to beans after creation. |
Create a test using the Testcontainers LocalStack module to start a LocalStack container and verify that the message has been sent and received.
package example.micronaut;
import io.micronaut.core.annotation.NonNull;
import io.micronaut.http.HttpRequest;
import io.micronaut.http.client.HttpClient;
import io.micronaut.http.client.annotation.Client;
import io.micronaut.test.extensions.junit5.annotation.MicronautTest;
import io.micronaut.test.support.TestPropertyProvider;
import jakarta.inject.Inject;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestInstance;
import org.testcontainers.containers.localstack.LocalStackContainer;
import org.testcontainers.utility.DockerImageName;
import java.util.Collections;
import java.util.Map;
import static org.awaitility.Awaitility.await;
import static org.hamcrest.Matchers.equalTo;
import static org.junit.jupiter.api.Assertions.assertEquals;
@MicronautTest (1)
@TestInstance(TestInstance.Lifecycle.PER_CLASS) (2)
class MicronautguideTest implements TestPropertyProvider { (3)
private static DockerImageName localstackImage = DockerImageName.parse("localstack/localstack:latest");
private static LocalStackContainer localstack = new LocalStackContainer(localstackImage)
.withServices(LocalStackContainer.Service.SQS);
@Override
public @NonNull Map<String, String> getProperties() {
if (!localstack.isRunning()) {
localstack.start();
}
return Map.of("aws.access-key-id", localstack.getAccessKey(),
"aws.secret-key", localstack.getSecretKey(),
"aws.region", localstack.getRegion(),
"aws.services.sqs.endpoint-override", localstack.getEndpointOverride(LocalStackContainer.Service.SQS).toString());
}
@Inject
@Client("/")
HttpClient httpClient;
@Inject
DemoConsumer demoConsumer;
@Test
void testItWorks() {
assertEquals(0, demoConsumer.getMessageCount());
httpClient.toBlocking().exchange(HttpRequest.POST("/demo", Collections.emptyMap()));
await().until(() -> demoConsumer.getMessageCount(), equalTo(1));
assertEquals(1, demoConsumer.getMessageCount());
}
}
1 | Annotate the class with @MicronautTest so the Micronaut framework will initialize the application context and the embedded server. More info. |
2 | Classes that implement TestPropertyProvider must use this annotation to create a single class instance for all tests (not necessary in Spock tests). |
3 | When you need dynamic properties definition, implement the TestPropertyProvider interface. Override the method .getProperties() and return the properties you want to expose to the application. |
7. Amazon Web Services (AWS)
If you don’t have one already, create an AWS Account.
7.1. AWS CLI
Follow the AWS documentation for installing or updating the latest version of the AWS CLI.
7.2. Administrator IAM user
Instead of using your AWS root account, it is recommended that you use an IAM administrative user. If you don’t have one already, follow the steps below to create one:
aws iam create-group --group-name Administrators
aws iam create-user --user-name Administrator
aws iam add-user-to-group --user-name Administrator --group-name Administrators
aws iam attach-group-policy --group-name Administrators --policy-arn $(aws iam list-policies --query 'Policies[?PolicyName==`AdministratorAccess`].{ARN:Arn}' --output text)
aws iam create-access-key --user-name Administrator
Then, run aws configure
to configure your AWS CLI to use the Administrator IAM user just created.
8. Creating a queue instance in Amazon Simple Queue Service (Amazon SQS)
You will create a queue with the AWS CLI. See the AWS CLI sqs
command for more information.
8.1. Create a queue instance
aws sqs create-queue --queue-name demo_queue
Copy and save the response of the command. You will need the QueueUrl
to delete the queue after you finish with it.
9. Running the Application
With almost everything in place, you can start the application and try it out. First, set environment variables to configure the queue connection. Then you can start the app.
Create environment variables for AWS_ACCESS_KEY_ID
, and AWS_SECRET_ACCESS_KEY
, as defined in AWS SDK Java v2 - Credential settings retrieval order:
export AWS_ACCESS_KEY_ID=<the access key from the AWS configuratipn step>
export AWS_SECRET_ACCESS_KEY=<the secret key from the AWS configuratipn step>
Window System
|
To run the application, use the ./mvnw mn:run
command, which starts the application on port 8080.
You can test the application in a web browser or with cURL.
Run from a terminal window to publish and consume a message:
curl "http://localhost:8080/demo"
9.1. Stopping the Instance and cleaning up
Once you are done with this guide, you can stop/delete the AWS resources created to avoid incurring unnecessary charges.
aws sqs delete-queue --queue-url <QUEUE_URL>
Replace the <QUEUE_URL>
placeholder with a queue URL value returned from the create-queue
command.
10. Generate a Micronaut Application Native Executable with GraalVM
We will use GraalVM, the polyglot embeddable virtual machine, to generate a native executable of our Micronaut application.
Compiling native executables ahead of time with GraalVM improves startup time and reduces the memory footprint of JVM-based applications.
Only Java and Kotlin projects support using GraalVM’s native-image tool. Groovy relies heavily on reflection, which is only partially supported by GraalVM.
|
10.1. GraalVM installation
sdk install java 17.0.12-graal
sdk use java 17.0.12-graal
For installation on Windows, or for manual installation on Linux or Mac, see the GraalVM Getting Started documentation.
The previous command installs Oracle GraalVM, which is free to use in production and free to redistribute, at no cost, under the GraalVM Free Terms and Conditions.
Alternatively, you can use the GraalVM Community Edition:
sdk install java 17.0.9-graalce
sdk use java 17.0.9-graalce
10.2. Native executable generation
To generate a native executable using Maven, run:
./mvnw package -Dpackaging=native-image
The native executable is created in the target
directory and can be run with target/micronautguide
.
Start the native executable and execute the same cURL request as before.
11. Next steps
Explore more features with Micronaut Guides.
Read more about Micronaut JMS.
Discover Amazon Simple Queue Service (SQS).
12. License
All guides are released with an Apache license 2.0 license for the code and a Creative Commons Attribution 4.0 license for the writing and media (images…). |