Amazon has SQS is fully managed Message Queuing Service, This is designed  to ease the exchanging messages between two systems. And this might helps to decouple the the system. For example  to trigger another lambda function which preforms some clean up task in the background or Scrape some data. reason for using the queue will be infinite.

So when it come using the queue is to send the message to the queue programmatically, So this article while guide you to send the message to the Queue from Java,

Step 1 : So Lets add the dependency required.

<dependency>
   <groupId>software.amazon.awssdk</groupId>
   <artifactId>sqs</artifactId>
   <version>2.16.14</version>
</dependency>

Step 2:  Next Step is to Setup the client which connects with AWS Credentials.

@Singleton
@Introspected
public class SQSBean {

    @Inject
    Environment env;

    @Bean
    @Primary
    public SqsClient getSqsClient() {
        AwsBasicCredentials credentials = AwsBasicCredentials.create(env.get("aws.clientId", String.class),
                env.get("aws.clientSecret", String.class));

        SqsClient client = SqsClient.builder().region(Region.US_EAST_1)
                .credentialsProvider(StaticCredentialsProvider.create(credentials)).build();
        return client;
    }


}

     Step 3 Writing The Adapter which Helps you to Send and receive the message.

@Singleton
public class SqsAdapter {
    @Inject
    SQSBean sqsClient;

    String url = "<Que url>";

    public <T> boolean  sendMessage(T body) {
        ObjectMapper mapper = new ObjectMapper();
        try {
            sqsClient.getSqsClient().sendMessage(SendMessageRequest.builder().queueUrl(url)
                    .messageBody(mapper.writeValueAsString(body)).build());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return true;
    }


    public <T> List<T>  receiveMessage(Class<T> className) {
        ObjectMapper mapper = new ObjectMapper();
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            
            sqsClient.getSqsClient().receiveMessage(ReceiveMessageRequest.builder().queueUrl(url).build());
            
            ReceiveMessageResponse message = sqsClient.getSqsClient().receiveMessage(ReceiveMessageRequest.builder().queueUrl(url).build());
           
            return message.messages().stream().map(m -> {
                try {
                    return mapper.readValue(m.body(),className);
                } catch (JsonProcessingException e) {
                    return null;
                }
            }).collect(Collectors.toList());
        } catch (Exception e) {
            e.printStackTrace();
            return  null;
           
        }
        
    }

}

The Adapter helps to send the the messages or receive the message to and fro from the queue.

So lets inject the the SqsAdapter   in controller or service and invoke the method `<>.SendMessage( new User("Test"))` to send some message and `<>.receiveMessage()` to recieve one.