为什么 snsClient.unsubscribe(request) 在 snsClient.unsubscribe(request) 上给我一个错误？

Question

I'm trying to use:

  UnsubscribeRequest request = UnsubscribeRequest.builder()
                .subscriptionArn("arn:aws:sns:us-east-1:9999999999:myTopic")
                .build();

  UnsubscribeResponse result = snsClient.unsubscribe(request);

But I received an error:

software.amazon.awssdk.services.sns.model.InvalidParameterException: Invalid parameter: SubscriptionId (Service: Sns, Status Code: 400, Request ID: 08d4fa07-be89-5b3d-bd81-a07bcf09de7a, Extended Request ID: null) at software.amazon.awssdk.core.internal.http.CombinedResponseHandler.handleErrorResponse(CombinedResponseHandler.java:123) ~[sdk-core-2.17.46.jar:na]

Can you help me to solve this problem?

Answer 1

You're using the ARN of the topic, not the ARN of the subscription. Each subscription has an ARN too. For example, if I create a topic named generic-topic the ARN for it looks like:

arn:aws:sns:us-west-2:1234567890:generic-topic

Then, when I create a subscription (in this case an SQS queue) the subscription ARN looks like:

arn:aws:sns:us-west-2:1234567890:generic-topic:dc1580a7-1234-4b3d-12340-abcd12345678

If you're using the CLI you can see the subscriptions for a topic with something like:

aws sns list-subscriptions-by-topic --topic-arn arn:aws:sns:us-west-2:1234567890:generic-topic

to get an output like:

{
    "Subscriptions": [
        {
            "SubscriptionArn": "arn:aws:sns:us-west-2:1234567890:generic-topic:dc1580a7-1234-4b3d-12340-abcd12345678",
            "Owner": "1234567890",
            "Protocol": "sqs",
            "Endpoint": "arn:aws:sqs:us-west-2:1234567890:generic-queue",
            "TopicArn": "arn:aws:sns:us-west-2:1234567890:generic-topic"
        }
    ]
}

Answer 2

To solve my problem I just get the subcription Id like this:

public String retornaSubscriptionArnSNS(String arnSns)  {
    
    String resultado = "";
    
    try {
        ListSubscriptionsRequest request = ListSubscriptionsRequest.builder()
                .build();

        ListSubscriptionsResponse result = snsClient.listSubscriptions(request);
        
        int intSize = result.subscriptions().size(); 
        
        if (intSize > 0) {
            
            for (int i = 0; i < intSize-1; i++) {
                
                if (result.subscriptions().get(0).topicArn().equals(arnSns)) {
                    
                    resultado = result.subscriptions().get(i).subscriptionArn();
                    System.out.println("I found my topic: "+resultado);
                    break; 
                }
                
            }  

            
        } else {
            System.out.println("No one subscription found");
        }

        if (resultado == "") {
            System.out.println("Topic not found");
        }
        
        
    } catch (SnsException e) {

        System.err.println(e.awsErrorDetails().errorMessage());
        System.exit(1);
    }
    return resultado;
    
}

Then you can call this method like this:

    retornaSubscriptionArnSNS("arn:aws:sns:us-east-1:9999999999:myTopic");

If the topic exists with subscription, then will print:

I found my topic: : arn:aws:sns:us-east-1:9999999999:myTopic:3e32b1c0-d3b7-40a6-8000-99220be49445

Else:

No one subscription found

I hope that code can be useful for you!