文件 AWS 開發套件範例 GitHub 儲存庫中有更多可用的 [AWS SDK 範例](https://github.com/awsdocs/aws-doc-sdk-examples)。

本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# 使用適用於 Ruby 的 SDK 的 Amazon SNS 範例
<a name="ruby_3_sns_code_examples"></a>

下列程式碼範例示範如何使用 適用於 Ruby 的 AWS SDK 搭配 Amazon SNS 執行動作和實作常見案例。

*Actions* 是大型程式的程式碼摘錄，必須在內容中執行。雖然動作會告訴您如何呼叫個別服務函數，但您可以在其相關情境中查看內容中的動作。

每個範例均包含完整原始碼的連結，您可在連結中找到如何設定和執行內容中程式碼的相關指示。

**Topics**
+ [動作](#actions)
+ [無伺服器範例](#serverless_examples)

## 動作
<a name="actions"></a>

### `CreateTopic`
<a name="sns_CreateTopic_ruby_3_topic"></a>

以下程式碼範例顯示如何使用 `CreateTopic`。

**SDK for Ruby**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/sns#code-examples)中設定和執行。

```
# This class demonstrates how to create an Amazon Simple Notification Service (SNS) topic.
class SNSTopicCreator
  # Initializes an SNS client.
  #
  # Utilizes the default AWS configuration for region and credentials.
  def initialize
    @sns_client = Aws::SNS::Client.new
  end

  # Attempts to create an SNS topic with the specified name.
  #
  # @param topic_name [String] The name of the SNS topic to create.
  # @return [Boolean] true if the topic was successfully created, false otherwise.
  def create_topic(topic_name)
    @sns_client.create_topic(name: topic_name)
    puts "The topic '#{topic_name}' was successfully created."
    true
  rescue Aws::SNS::Errors::ServiceError => e
    # Handles SNS service errors gracefully.
    puts "Error while creating the topic named '#{topic_name}': #{e.message}"
    false
  end
end

# Example usage:
if $PROGRAM_NAME == __FILE__
  topic_name = 'YourTopicName' # Replace with your topic name
  sns_topic_creator = SNSTopicCreator.new

  puts "Creating the topic '#{topic_name}'..."
  unless sns_topic_creator.create_topic(topic_name)
    puts 'The topic was not created. Stopping program.'
    exit 1
  end
end
```
+  如需詳細資訊，請參閱《[適用於 Ruby 的 AWS SDK 開發人員指南](https://docs.aws.amazon.com/sdk-for-ruby/v3/developer-guide/sns-example-create-topic.html)》。
+  如需 API 詳細資訊，請參閱《適用於 Ruby 的 AWS SDK API 參考》**中的 [CreateTopic](https://docs.aws.amazon.com/goto/SdkForRubyV3/sns-2010-03-31/CreateTopic)。

### `ListSubscriptions`
<a name="sns_ListSubscriptions_ruby_3_topic"></a>

以下程式碼範例顯示如何使用 `ListSubscriptions`。

**SDK for Ruby**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/sns#code-examples)中設定和執行。

```
# This class demonstrates how to list subscriptions to an Amazon Simple Notification Service (SNS) topic
class SnsSubscriptionLister
  def initialize(sns_client)
    @sns_client = sns_client
    @logger = Logger.new($stdout)
  end

  # Lists subscriptions for a given SNS topic
  # @param topic_arn [String] The ARN of the SNS topic
  # @return [Types::ListSubscriptionsResponse] subscriptions: The response object
  def list_subscriptions(topic_arn)
    @logger.info("Listing subscriptions for topic: #{topic_arn}")
    subscriptions = @sns_client.list_subscriptions_by_topic(topic_arn: topic_arn)
    subscriptions.subscriptions.each do |subscription|
      @logger.info("Subscription endpoint: #{subscription.endpoint}")
    end
    subscriptions
  rescue Aws::SNS::Errors::ServiceError => e
    @logger.error("Error listing subscriptions: #{e.message}")
    raise
  end
end

# Example usage:
if $PROGRAM_NAME == __FILE__
  sns_client = Aws::SNS::Client.new
  topic_arn = 'SNS_TOPIC_ARN' # Replace with your SNS topic ARN
  lister = SnsSubscriptionLister.new(sns_client)

  begin
    lister.list_subscriptions(topic_arn)
  rescue StandardError => e
    puts "Failed to list subscriptions: #{e.message}"
    exit 1
  end
end
```
+  如需詳細資訊，請參閱《[適用於 Ruby 的 AWS SDK 開發人員指南](https://docs.aws.amazon.com/sdk-for-ruby/v3/developer-guide/sns-example-show-subscriptions.html)》。
+  如需 API 詳細資訊，請參閱 *適用於 Ruby 的 AWS SDK API 參考*中的 [ListSubscriptions](https://docs.aws.amazon.com/goto/SdkForRubyV3/sns-2010-03-31/ListSubscriptions)。

### `ListTopics`
<a name="sns_ListTopics_ruby_3_topic"></a>

以下程式碼範例顯示如何使用 `ListTopics`。

**SDK for Ruby**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/sns#code-examples)中設定和執行。

```
require 'aws-sdk-sns' # v2: require 'aws-sdk'

def list_topics?(sns_client)
  sns_client.topics.each do |topic|
    puts topic.arn
  rescue StandardError => e
    puts "Error while listing the topics: #{e.message}"
  end
end

def run_me
  region = 'REGION'
  sns_client = Aws::SNS::Resource.new(region: region)

  puts 'Listing the topics.'

  return if list_topics?(sns_client)

  puts 'The bucket was not created. Stopping program.'
  exit 1
end

# Example usage:
run_me if $PROGRAM_NAME == __FILE__
```
+  如需詳細資訊，請參閱《[適用於 Ruby 的 AWS SDK 開發人員指南](https://docs.aws.amazon.com/sdk-for-ruby/v3/developer-guide/sns-example-show-topics.html)》。
+  如需 API 詳細資訊，請參閱 *適用於 Ruby 的 AWS SDK API 參考*中的 [ListTopics](https://docs.aws.amazon.com/goto/SdkForRubyV3/sns-2010-03-31/ListTopics)。

### `Publish`
<a name="sns_Publish_ruby_3_topic"></a>

以下程式碼範例顯示如何使用 `Publish`。

**SDK for Ruby**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/sns#code-examples)中設定和執行。

```
# Service class for sending messages using Amazon Simple Notification Service (SNS)
class SnsMessageSender
  # Initializes the SnsMessageSender with an SNS client
  #
  # @param sns_client [Aws::SNS::Client] The SNS client
  def initialize(sns_client)
    @sns_client = sns_client
    @logger = Logger.new($stdout)
  end

  # Sends a message to a specified SNS topic
  #
  # @param topic_arn [String] The ARN of the SNS topic
  # @param message [String] The message to send
  # @return [Boolean] true if message was successfully sent, false otherwise
  def send_message(topic_arn, message)
    @sns_client.publish(topic_arn: topic_arn, message: message)
    @logger.info("Message sent successfully to #{topic_arn}.")
    true
  rescue Aws::SNS::Errors::ServiceError => e
    @logger.error("Error while sending the message: #{e.message}")
    false
  end
end

# Example usage:
if $PROGRAM_NAME == __FILE__
  topic_arn = 'SNS_TOPIC_ARN' # Should be replaced with a real topic ARN
  message = 'MESSAGE'         # Should be replaced with the actual message content

  sns_client = Aws::SNS::Client.new
  message_sender = SnsMessageSender.new(sns_client)

  @logger.info('Sending message.')
  unless message_sender.send_message(topic_arn, message)
    @logger.error('Message sending failed. Stopping program.')
    exit 1
  end
end
```
+  如需詳細資訊，請參閱《[適用於 Ruby 的 AWS SDK 開發人員指南](https://docs.aws.amazon.com/sdk-for-ruby/v3/developer-guide/sns-example-send-message.html)》。
+  如需 API 詳細資訊，請參閱 *適用於 Ruby 的 AWS SDK API 參考*中的[發佈](https://docs.aws.amazon.com/goto/SdkForRubyV3/sns-2010-03-31/Publish)。

### `SetTopicAttributes`
<a name="sns_SetTopicAttributes_ruby_3_topic"></a>

以下程式碼範例顯示如何使用 `SetTopicAttributes`。

**SDK for Ruby**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/sns#code-examples)中設定和執行。

```
# Service class to enable an SNS resource with a specified policy
class SnsResourceEnabler
  # Initializes the SnsResourceEnabler with an SNS resource client
  #
  # @param sns_resource [Aws::SNS::Resource] The SNS resource client
  def initialize(sns_resource)
    @sns_resource = sns_resource
    @logger = Logger.new($stdout)
  end

  # Sets a policy on a specified SNS topic
  #
  # @param topic_arn [String] The ARN of the SNS topic
  # @param resource_arn [String] The ARN of the resource to include in the policy
  # @param policy_name [String] The name of the policy attribute to set
  def enable_resource(topic_arn, resource_arn, policy_name)
    policy = generate_policy(topic_arn, resource_arn)
    topic = @sns_resource.topic(topic_arn)

    topic.set_attributes({
                           attribute_name: policy_name,
                           attribute_value: policy
                         })
    @logger.info("Policy #{policy_name} set successfully for topic #{topic_arn}.")
  rescue Aws::SNS::Errors::ServiceError => e
    @logger.error("Failed to set policy: #{e.message}")
  end

  private

  # Generates a policy string with dynamic resource ARNs
  #
  # @param topic_arn [String] The ARN of the SNS topic
  # @param resource_arn [String] The ARN of the resource
  # @return [String] The policy as a JSON string
  def generate_policy(topic_arn, resource_arn)
    {
      Version: '2008-10-17',
      Id: '__default_policy_ID',
      Statement: [{
        Sid: '__default_statement_ID',
        Effect: 'Allow',
        Principal: { "AWS": '*' },
        Action: ['SNS:Publish'],
        Resource: topic_arn,
        Condition: {
          ArnEquals: {
            "AWS:SourceArn": resource_arn
          }
        }
      }]
    }.to_json
  end
end

# Example usage:
if $PROGRAM_NAME == __FILE__
  topic_arn = 'MY_TOPIC_ARN' # Should be replaced with a real topic ARN
  resource_arn = 'MY_RESOURCE_ARN' # Should be replaced with a real resource ARN
  policy_name = 'POLICY_NAME' # Typically, this is "Policy"

  sns_resource = Aws::SNS::Resource.new
  enabler = SnsResourceEnabler.new(sns_resource)

  enabler.enable_resource(topic_arn, resource_arn, policy_name)
end
```
+  如需詳細資訊，請參閱《[適用於 Ruby 的 AWS SDK 開發人員指南](https://docs.aws.amazon.com/sdk-for-ruby/v3/developer-guide/sns-example-enable-resource.html)》。
+  如需 API 詳細資訊，請參閱 *適用於 Ruby 的 AWS SDK API 參考*中的 [SetTopicAttributes](https://docs.aws.amazon.com/goto/SdkForRubyV3/sns-2010-03-31/SetTopicAttributes)。

### `Subscribe`
<a name="sns_Subscribe_ruby_3_topic"></a>

以下程式碼範例顯示如何使用 `Subscribe`。

**SDK for Ruby**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/sns#code-examples)中設定和執行。
透過電子郵件地址訂閱某個主題。  

```
require 'aws-sdk-sns'
require 'logger'

# Represents a service for creating subscriptions in Amazon Simple Notification Service (SNS)
class SubscriptionService
  # Initializes the SubscriptionService with an SNS client
  #
  # @param sns_client [Aws::SNS::Client] The SNS client
  def initialize(sns_client)
    @sns_client = sns_client
    @logger = Logger.new($stdout)
  end

  # Attempts to create a subscription to a topic
  #
  # @param topic_arn [String] The ARN of the SNS topic
  # @param protocol [String] The subscription protocol (e.g., email)
  # @param endpoint [String] The endpoint that receives the notifications (email address)
  # @return [Boolean] true if subscription was successfully created, false otherwise
  def create_subscription(topic_arn, protocol, endpoint)
    @sns_client.subscribe(topic_arn: topic_arn, protocol: protocol, endpoint: endpoint)
    @logger.info('Subscription created successfully.')
    true
  rescue Aws::SNS::Errors::ServiceError => e
    @logger.error("Error while creating the subscription: #{e.message}")
    false
  end
end

# Main execution if the script is run directly
if $PROGRAM_NAME == __FILE__
  protocol = 'email'
  endpoint = 'EMAIL_ADDRESS' # Should be replaced with a real email address
  topic_arn = 'TOPIC_ARN'    # Should be replaced with a real topic ARN

  sns_client = Aws::SNS::Client.new
  subscription_service = SubscriptionService.new(sns_client)

  @logger.info('Creating the subscription.')
  unless subscription_service.create_subscription(topic_arn, protocol, endpoint)
    @logger.error('Subscription creation failed. Stopping program.')
    exit 1
  end
end
```
+  如需詳細資訊，請參閱《[適用於 Ruby 的 AWS SDK 開發人員指南](https://docs.aws.amazon.com/sdk-for-ruby/v3/developer-guide/sns-example-create-subscription.html)》。
+  如需 API 詳細資訊，請參閱《適用於 Ruby 的 AWS SDK API 參考》**中的[訂閱](https://docs.aws.amazon.com/goto/SdkForRubyV3/sns-2010-03-31/Subscribe)。

## 無伺服器範例
<a name="serverless_examples"></a>

### 使用 Amazon SNS 觸發條件調用 Lambda 函數
<a name="serverless_SNS_Lambda_ruby_3_topic"></a>

下列程式碼範例示範如何實作 Lambda 函式，該函式會透過接收 SNS 主題的訊息來接收所觸發的事件。函數會從事件參數擷取訊息，並記錄每一則訊息的內容。

**SDK for Ruby**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在[無伺服器範例](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda)儲存庫中設定和執行。
使用 Ruby 搭配 Lambda 來使用 SNS 事件。  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event:, context:)
  event['Records'].map { |record| process_message(record) }
end

def process_message(record)
  message = record['Sns']['Message']
  puts("Processing message: #{message}")
rescue StandardError => e
  puts("Error processing message: #{e}")
  raise
end
```