com.amazonaws.services.sns.util

Class Topics

java.lang.Object

com.amazonaws.services.sns.util.Topics

public class Topics
extends Object

Set of utility methods for working with Amazon SNS topics.

Constructor Summary

Constructors

Constructor and Description
Topics()

Method Summary

Methods

Modifier and Type	Method and Description
static String	subscribeQueue(AmazonSNS sns, AmazonSQS sqs, String snsTopicArn, String sqsQueueUrl) Subscribes an existing Amazon SQS queue to an existing Amazon SNS topic.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Topics

public Topics()

Method Detail

subscribeQueue

public static String subscribeQueue(AmazonSNS sns,
                    AmazonSQS sqs,
                    String snsTopicArn,
                    String sqsQueueUrl)
                             throws AmazonClientException,
                                    AmazonServiceException

Subscribes an existing Amazon SQS queue to an existing Amazon SNS topic.

The specified Amazon SNS client will be used to send the subscription request, and the Amazon SQS client will be used to modify the policy on the queue to allow it to receive messages from the SNS topic.

The policy applied to the SQS queue is similar to this:

 {
    "Version" : "2008-10-17",
    "Statement" : [{
       "Sid" : "topic-subscription-arn:aws:sns:us-west-2:599109622955:myTopic",
       "Effect" : "Allow",
       "Principal" : {
          "AWS":["*"]
       },
       "Action" : ["sqs:SendMessage"],
       "Resource":["arn:aws:sqs:us-west-2:599109622955:myQueue"],
       "Condition" : {
          "ArnLike":{
             "aws:SourceArn":["arn:aws:sns:us-west-2:599109622955:myTopic"]
          }
       }
    }]
 }
 

IMPORTANT: If there is already an existing policy set for the specified SQS queue, this operation will overwrite it with a new policy that allows the SNS topic to deliver messages to the queue.

IMPORTANT: There might be a small time period immediately after subscribing the SQS queue to the SNS topic and updating the SQS queue's policy, where messages are not able to be delivered to the queue. After a moment, the new queue policy will propagate and the queue will be able to receive messages. This delay only occurs immediately after initially subscribing the queue.

IMPORTANT: The specified queue and topic (as well as the SNS and SQS client) should both be located in the same AWS region.

Parameters:

sns - The Amazon SNS client to use when subscribing the queue to the topic.

sqs - The Amazon SQS client to use when applying the policy to allow subscribing to the topic.

snsTopicArn - The Amazon Resource Name (ARN) uniquely identifying the Amazon SNS topic. This value is returned form Amazon SNS when creating the topic.

sqsQueueUrl - The URL uniquely identifying the Amazon SQS queue. This value is returned from Amazon SQS when creating the queue.

Returns:

The subscription ARN as returned by Amazon SNS when the queue is successfully subscribed to the topic.

Throws:

AmazonClientException - If any internal errors are encountered inside the client while attempting to make the request or handle the response. For example if a network connection is not available.

AmazonServiceException - If an error response is returned by AmazonSNS indicating either a problem with the data in the request, or a server side issue.