Amazon SQS abfrage

[ProgrammNiklas]

Moin, in meinem Code zur Abfrage von Amazon SQS funktioniert soweit alles außer das ich nach ein paar mal ausführen den Fehlercode
java.lang.IndexOutOfBoundsException: Index 0 out of bounds for length 0
bekomme.
Weiß da jemand eine Lösung?

package com.company;
import java.util.*;
import java.util.concurrent.TimeUnit;

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.sqs.AmazonSQSClientBuilder;
import com.amazonaws.services.sqs.model.CreateQueueRequest;
import com.amazonaws.services.sqs.model.DeleteMessageRequest;
import com.amazonaws.services.sqs.model.GetQueueAttributesRequest;
import com.amazonaws.services.sqs.model.GetQueueAttributesResult;
import com.amazonaws.services.sqs.model.MessageAttributeValue;
import com.amazonaws.services.sqs.model.ReceiveMessageRequest;
import com.amazonaws.services.sqs.model.SendMessageBatchRequest;
import com.amazonaws.services.sqs.model.SendMessageRequest;
import com.amazonaws.services.sqs.model.SetQueueAttributesRequest;
import com.amazonaws.services.sqs.model.SendMessageBatchRequestEntry;
import com.amazonaws.services.sqs.model.Message;
import com.amazonaws.services.sqs.AmazonSQS;

public class Main {


    private static final AWSCredentials credentials;


    static {
        // accesskey + secretkey
        credentials = new BasicAWSCredentials("", "");
    }


    public static void main(String[] args) {

      try {



        boolean repeat = true;
        Scanner scan = new Scanner(System.in);



        AmazonSQS sqs = AmazonSQSClientBuilder.standard()
                .withCredentials(new AWSStaticCredentialsProvider(credentials))
                .withRegion(Regions.US_EAST_1)
                .build();

        int i = 0;

                while (i < 6) {

        CreateQueueRequest createStandardQueueRequest = new CreateQueueRequest("baeldung-queue");
        String standardQueueUrl = sqs.createQueue(createStandardQueueRequest).getQueueUrl();



        // Create a fifo queue

        Map<String, String> queueAttributes = new HashMap<>();
        queueAttributes.put("FifoQueue", "true");
        queueAttributes.put("ContentBasedDeduplication", "true");

        CreateQueueRequest createFifoQueueRequest = new CreateQueueRequest("baeldung-queue.fifo").withAttributes(queueAttributes);
        String fifoQueueUrl = sqs.createQueue(createFifoQueueRequest).getQueueUrl();



        // Set up a dead letter queue

        String deadLetterQueueUrl = sqs.createQueue("baeldung-dead-letter-queue").getQueueUrl();

        GetQueueAttributesResult deadLetterQueueAttributes = sqs.getQueueAttributes(new GetQueueAttributesRequest(deadLetterQueueUrl).withAttributeNames("QueueArn"));

        String deadLetterQueueARN = deadLetterQueueAttributes.getAttributes().get("QueueArn");

        SetQueueAttributesRequest queueAttributesRequest = new SetQueueAttributesRequest().withQueueUrl(standardQueueUrl)
                .addAttributesEntry("RedrivePolicy", "{\"maxReceiveCount\":\"2\", " + "\"deadLetterTargetArn\":\"" + deadLetterQueueARN + "\"}");

        sqs.setQueueAttributes(queueAttributesRequest);

        // Send a message to a standard queue

        Map<String, MessageAttributeValue> messageAttributes = new HashMap<>();

        messageAttributes.put("AttributeOne", new MessageAttributeValue().withStringValue("This is an attribute").withDataType("String"));

        SendMessageRequest sendMessageStandardQueue = new SendMessageRequest().withQueueUrl(standardQueueUrl)
                .withMessageBody("A simple message.")
                .withDelaySeconds(30) // Message will arrive in the queue after 30 seconds. We can use this only in standard queues
                .withMessageAttributes(messageAttributes);

        sqs.sendMessage(sendMessageStandardQueue);

        // Send a message to a fifo queue

        SendMessageRequest sendMessageFifoQueue = new SendMessageRequest().withQueueUrl(fifoQueueUrl).withMessageBody("FIFO Queue").withMessageGroupId("baeldung-group-1").withMessageAttributes(messageAttributes);

        sqs.sendMessage(sendMessageFifoQueue);

        // Send multiple messages

        List<SendMessageBatchRequestEntry> messageEntries = new ArrayList<>();
        messageEntries.add(new SendMessageBatchRequestEntry().withId("id-1").withMessageBody("batch-1").withMessageGroupId("baeldung-group-1"));
        messageEntries.add(new SendMessageBatchRequestEntry().withId("id-2").withMessageBody("batch-2").withMessageGroupId("baeldung-group-1"));


        SendMessageBatchRequest sendMessageBatchRequest = new SendMessageBatchRequest(fifoQueueUrl, messageEntries);
        sqs.sendMessageBatch(sendMessageBatchRequest);

        // Read a message from a queue


        ReceiveMessageRequest receiveMessageRequest = new ReceiveMessageRequest(fifoQueueUrl).withWaitTimeSeconds(10).withMaxNumberOfMessages(1); //max 10

        final List<Message> sqsMessages = sqs.receiveMessage(receiveMessageRequest).getMessages();



                       sqsMessages.get(0).getMessageAttributes();
                        sqsMessages.get(0).getBody();














        // Delete a message from a queue

        sqs.deleteMessage(new DeleteMessageRequest().withQueueUrl(fifoQueueUrl).withReceiptHandle(sqsMessages.get(0).getReceiptHandle()));



        // Monitoring


        GetQueueAttributesRequest getQueueAttributesRequest = new GetQueueAttributesRequest(standardQueueUrl).withAttributeNames("All");
        GetQueueAttributesResult getQueueAttributesResult = sqs.getQueueAttributes(getQueueAttributesRequest);





                        System.out.println(String.format("The number of messages on the queue: %s", getQueueAttributesResult.getAttributes().get("ApproximateNumberOfMessages")));
                        System.out.println(String.format("The number of messages in flight: %s", getQueueAttributesResult.getAttributes().get("ApproximateNumberOfMessagesNotVisible")));




        try {

            TimeUnit.SECONDS.sleep(3);

        } catch (Exception exception) {

        }

        i++;
    }


      } catch(Exception e) {
          System.out.println(e);
      }
}





}

 

[temi]

Anscheinend ist hier nichts drin: sqsMessages.get(0).getMessageAttributes();

Prüfe vor dem Zugriff, ob Daten enthalten sind.

Das ist aber nur eine Vermutung, beim Überfliegen des Codes. Ich empfehle den Umgang mit dem Debugger zu üben.

Die Fehlermeldung an sich sollte ja kein Problem darstellen: Du versuchst auf den kleinsten Index einer Liste (oder Array) zuzugreifen und die Liste hat die Länge Null (= kein Inhalt).