Sending, receiving, and deleting Amazon Simple Queue Service messages

A message is a piece of data that can be sent and received by distributed components. Messages are always delivered using an SQS Queue.

Send a message

Add a single message to an Amazon Simple Queue Service queue by calling the SqsClient client sendMessage method. Provide a SendMessageRequest object that contains the queue’s URL, message body, and optional delay value (in seconds).

Imports

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.sqs.SqsClient;
import software.amazon.awssdk.services.sqs.model.*;
import java.util.List;

Code

            sqsClient.sendMessage(SendMessageRequest.builder()
                .queueUrl(queueUrl)
                .messageBody("Hello world!")
                .delaySeconds(10)
                .build());

Send multiple messages in a request

Send more than one message in a single request by using the SqsClient sendMessageBatch method. This method takes a SendMessageBatchRequest that contains the queue URL and a list of messages to send. (Each message is a SendMessageBatchRequestEntry.) You can also delay sending a specific message by setting a delay value on the message.

Imports

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.sqs.SqsClient;
import software.amazon.awssdk.services.sqs.model.*;
import java.util.List;

Code

            SendMessageBatchRequest sendMessageBatchRequest = SendMessageBatchRequest.builder()
                .queueUrl(queueUrl)
                .entries(SendMessageBatchRequestEntry.builder().id("id1").messageBody("Hello from msg 1").build(),
                        SendMessageBatchRequestEntry.builder().id("id2").messageBody("msg 2").delaySeconds(10).build())
                .build();
            sqsClient.sendMessageBatch(sendMessageBatchRequest);

See the complete sample on GitHub.

Retrieve Messages

Retrieve any messages that are currently in the queue by calling the SqsClient receiveMessage method. This method takes a ReceiveMessageRequest that contains the queue URL. You can also specify the maximum number of messages to return. Messages are returned as a list of Message objects.

Imports

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.sqs.SqsClient;
import software.amazon.awssdk.services.sqs.model.*;
import java.util.List;

Code

            ReceiveMessageRequest receiveMessageRequest = ReceiveMessageRequest.builder()
                .queueUrl(queueUrl)
                .maxNumberOfMessages(5)
                .build();
            List<Message> messages = sqsClient.receiveMessage(receiveMessageRequest).messages();
            return messages;
        } catch (SqsException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
        return null;

Delete a message after receipt

After receiving a message and processing its contents, delete the message from the queue by sending the message’s receipt handle and queue URL to the SqsClient deleteMessage method.

Imports

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.sqs.SqsClient;
import software.amazon.awssdk.services.sqs.model.*;
import java.util.List;

Code

        try {
            for (Message message : messages) {
                DeleteMessageRequest deleteMessageRequest = DeleteMessageRequest.builder()
                    .queueUrl(queueUrl)
                    .receiptHandle(message.receiptHandle())
                    .build();
                sqsClient.deleteMessage(deleteMessageRequest);
            }

See the complete sample on GitHub.

More Info

• How Amazon Simple Queue Service Queues Work in the Amazon Simple Queue Service Developer Guide

• SendMessage in the Amazon Simple Queue Service API Reference

• SendMessageBatch in the Amazon Simple Queue Service API Reference

• ReceiveMessage in the Amazon Simple Queue Service API Reference

• DeleteMessage in the Amazon Simple Queue Service API Reference