Ricevi ed elabora le notifiche degli eventi di Amazon S3 utilizzando un AWS SDK.

Il seguente esempio di codice mostra come utilizzare le notifiche di eventi S3 in modo orientato agli oggetti.

Java

SDKper Java 2.x

Nota

C'è altro su. GitHub Trova l'esempio completo e scopri come configurare ed eseguire in AWS Repository di esempi di codice.

Questo esempio mostra come elaborare un evento di notifica S3 utilizzando AmazonSQS.

    /**
     * This method receives S3 event notifications by using an SqsAsyncClient.
     * After the client receives the messages it deserializes the JSON payload and logs them. It uses
     * the S3EventNotification class (part of the S3 event notification API for Java) to deserialize
     * the JSON payload and access the messages in an object-oriented way.
     *
     * @param queueUrl The URL of the AWS SQS queue that receives the S3 event notifications.
     * @see <a href="https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/eventnotifications/s3/model/package-summary.html">S3EventNotification API</a>.
     * <p>
     * To use S3 event notification serialization/deserialization to objects, add the following
     * dependency to your Maven pom.xml file.
     * <dependency>
     * <groupId>software.amazon.awssdk</groupId>
     * <artifactId>s3-event-notifications</artifactId>
     * <version><LATEST></version>
     * </dependency>
     * <p>
     * The S3 event notification API became available with version 2.25.11 of the Java SDK.
     * <p>
     * This example shows the use of the API with AWS SQS, but it can be used to process S3 event notifications
     * in AWS SNS or AWS Lambda as well.
     * <p>
     * Note: The S3EventNotification class does not work with messages routed through AWS EventBridge.
     */
    static void processS3Events(String bucketName, String queueUrl, String queueArn) {
        try {
            // Configure the bucket to send Object Created and Object Tagging notifications to an existing SQS queue.
            s3Client.putBucketNotificationConfiguration(b -> b
                    .notificationConfiguration(ncb -> ncb
                            .queueConfigurations(qcb -> qcb
                                    .events(Event.S3_OBJECT_CREATED, Event.S3_OBJECT_TAGGING)
                                    .queueArn(queueArn)))
                            .bucket(bucketName)
            ).join();

            triggerS3EventNotifications(bucketName);
            // Wait for event notifications to propagate.
            Thread.sleep(Duration.ofSeconds(5).toMillis());

            boolean didReceiveMessages = true;
            while (didReceiveMessages) {
                // Display the number of messages that are available in the queue.
                sqsClient.getQueueAttributes(b -> b
                                .queueUrl(queueUrl)
                                .attributeNames(QueueAttributeName.APPROXIMATE_NUMBER_OF_MESSAGES)
                        ).thenAccept(attributeResponse ->
                                logger.info("Approximate number of messages in the queue: {}",
                                        attributeResponse.attributes().get(QueueAttributeName.APPROXIMATE_NUMBER_OF_MESSAGES)))
                        .join();

                // Receive the messages.
                ReceiveMessageResponse response = sqsClient.receiveMessage(b -> b
                        .queueUrl(queueUrl)
                ).get();
                logger.info("Count of received messages: {}", response.messages().size());
                didReceiveMessages = !response.messages().isEmpty();

                // Create a collection to hold the received message for deletion
                // after we log the messages.
                HashSet<DeleteMessageBatchRequestEntry> messagesToDelete = new HashSet<>();
                // Process each message.
                response.messages().forEach(message -> {
                    logger.info("Message id: {}", message.messageId());
                    // Deserialize JSON message body to a S3EventNotification object
                    // to access messages in an object-oriented way.
                    S3EventNotification event = S3EventNotification.fromJson(message.body());

                    // Log the S3 event notification record details.
                    if (event.getRecords() != null) {
                        event.getRecords().forEach(record -> {
                            String eventName = record.getEventName();
                            String key = record.getS3().getObject().getKey();
                            logger.info(record.toString());
                            logger.info("Event name is {} and key is {}", eventName, key);
                        });
                    }
                    // Add logged messages to collection for batch deletion.
                    messagesToDelete.add(DeleteMessageBatchRequestEntry.builder()
                            .id(message.messageId())
                            .receiptHandle(message.receiptHandle())
                            .build());
                });
                // Delete messages.
                if (!messagesToDelete.isEmpty()) {
                    sqsClient.deleteMessageBatch(DeleteMessageBatchRequest.builder()
                            .queueUrl(queueUrl)
                            .entries(messagesToDelete)
                            .build()
                    ).join();
                }
            } // End of while block.
        } catch (InterruptedException | ExecutionException e) {
            throw new RuntimeException(e);
        }
    }

• Per API i dettagli, consulta i seguenti argomenti in AWS SDK for Java 2.x APIRiferimento.

  • DeleteMessageBatch

  • GetQueueAttributes

  • PutBucketNotificationConfiguration

  • ReceiveMessage

Per un elenco completo di AWS SDKguide per sviluppatori ed esempi di codice, vediUtilizzo di questo servizio con un SDK AWS. Questo argomento include anche informazioni su come iniziare e dettagli sulle SDK versioni precedenti.