AWS SDK を使用して、Amazon S3 で Amazon SNS に大きなメッセージを発行する

次のコード例は、Amazon S3 を使用してメッセージペイロードを保存する大きなメッセージを Amazon SNS に発行する方法を示しています。

Java

SDK for Java 1.x

注記

については、こちらを参照してください GitHub。用例一覧を検索し、AWS コードサンプルリポジトリでの設定と実行の方法を確認してください。

容量の大きなメッセージを発行するには、Amazon SNS Extended Client Library for Java を使用します。送信するメッセージは、実際のメッセージコンテンツを含む Amazon S3 オブジェクトをリファレンスします。

import com.amazon.sqs.javamessaging.AmazonSQSExtendedClient;
import com.amazon.sqs.javamessaging.ExtendedClientConfiguration;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.sns.AmazonSNS;
import com.amazonaws.services.sns.AmazonSNSClientBuilder;
import com.amazonaws.services.sns.model.CreateTopicRequest;
import com.amazonaws.services.sns.model.PublishRequest;
import com.amazonaws.services.sns.model.SetSubscriptionAttributesRequest;
import com.amazonaws.services.sns.util.Topics;
import com.amazonaws.services.sqs.AmazonSQS;
import com.amazonaws.services.sqs.AmazonSQSClientBuilder;
import com.amazonaws.services.sqs.model.CreateQueueRequest;
import com.amazonaws.services.sqs.model.ReceiveMessageResult;
import software.amazon.sns.AmazonSNSExtendedClient;
import software.amazon.sns.SNSExtendedClientConfiguration;

public class Example {

        public static void main(String[] args) {
                final String BUCKET_NAME = "extended-client-bucket";
                final String TOPIC_NAME = "extended-client-topic";
                final String QUEUE_NAME = "extended-client-queue";
                final Regions region = Regions.DEFAULT_REGION;

                // Message threshold controls the maximum message size that will be allowed to
                // be published
                // through SNS using the extended client. Payload of messages exceeding this
                // value will be stored in
                // S3. The default value of this parameter is 256 KB which is the maximum
                // message size in SNS (and SQS).
                final int EXTENDED_STORAGE_MESSAGE_SIZE_THRESHOLD = 32;

                // Initialize SNS, SQS and S3 clients
                final AmazonSNS snsClient = AmazonSNSClientBuilder.standard().withRegion(region).build();
                final AmazonSQS sqsClient = AmazonSQSClientBuilder.standard().withRegion(region).build();
                final AmazonS3 s3Client = AmazonS3ClientBuilder.standard().withRegion(region).build();

                // Create bucket, topic, queue and subscription
                s3Client.createBucket(BUCKET_NAME);
                final String topicArn = snsClient.createTopic(
                                new CreateTopicRequest().withName(TOPIC_NAME)).getTopicArn();
                final String queueUrl = sqsClient.createQueue(
                                new CreateQueueRequest().withQueueName(QUEUE_NAME)).getQueueUrl();
                final String subscriptionArn = Topics.subscribeQueue(
                                snsClient, sqsClient, topicArn, queueUrl);

                // To read message content stored in S3 transparently through SQS extended
                // client,
                // set the RawMessageDelivery subscription attribute to TRUE
                final SetSubscriptionAttributesRequest subscriptionAttributesRequest = new SetSubscriptionAttributesRequest();
                subscriptionAttributesRequest.setSubscriptionArn(subscriptionArn);
                subscriptionAttributesRequest.setAttributeName("RawMessageDelivery");
                subscriptionAttributesRequest.setAttributeValue("TRUE");
                snsClient.setSubscriptionAttributes(subscriptionAttributesRequest);

                // Initialize SNS extended client
                // PayloadSizeThreshold triggers message content storage in S3 when the
                // threshold is exceeded
                // To store all messages content in S3, use AlwaysThroughS3 flag
                final SNSExtendedClientConfiguration snsExtendedClientConfiguration = new SNSExtendedClientConfiguration()
                                .withPayloadSupportEnabled(s3Client, BUCKET_NAME)
                                .withPayloadSizeThreshold(EXTENDED_STORAGE_MESSAGE_SIZE_THRESHOLD);
                final AmazonSNSExtendedClient snsExtendedClient = new AmazonSNSExtendedClient(snsClient,
                                snsExtendedClientConfiguration);

                // Publish message via SNS with storage in S3
                final String message = "This message is stored in S3 as it exceeds the threshold of 32 bytes set above.";
                snsExtendedClient.publish(topicArn, message);

                // Initialize SQS extended client
                final ExtendedClientConfiguration sqsExtendedClientConfiguration = new ExtendedClientConfiguration()
                                .withPayloadSupportEnabled(s3Client, BUCKET_NAME);
                final AmazonSQSExtendedClient sqsExtendedClient = new AmazonSQSExtendedClient(sqsClient,
                                sqsExtendedClientConfiguration);

                // Read the message from the queue
                final ReceiveMessageResult result = sqsExtendedClient.receiveMessage(queueUrl);
                System.out.println("Received message is " + result.getMessages().get(0).getBody());
        }
}