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Understanding InvalidS3KeyException in AWS Polly

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By Exception Decoded 3 min read

AWS Polly is a service that turns text into lifelike speech, allowing developers to create applications that talk. While working with this powerful text-to-speech service, you may encounter the InvalidS3KeyException from the com.amazonaws.services.polly.model package. In this article, we will dive deep into this exception, its causes, and how to resolve it with practical code examples.

What is InvalidS3KeyException?

The InvalidS3KeyException is thrown when the Amazon Polly service attempts to access a voice’s audio file stored in an Amazon S3 bucket, but the specified S3 key (the path to the file) is not valid or accessible. This can happen due to various reasons, including incorrect S3 bucket permissions, an incorrect path, or a missing key.

Common Causes

  1. Incorrect S3 Key: The path to the audio file may be malformed or point to a file that does not exist.
  2. Invalid Bucket Name: The bucket name specified might not exist or may be incorrectly spelled.
  3. Permissions Issues: The IAM role or user that your application uses to access AWS Polly might not have the necessary permissions to read from the specified S3 bucket.

Resolving InvalidS3KeyException

To resolve the InvalidS3KeyException, follow these steps:

  1. Verify the S3 Key: Ensure the path to the audio file is correct and that the file exists in the specified S3 bucket.
  2. Check Bucket Permissions: Make sure that the permissions attached to your S3 bucket allow read access for the IAM role or user that your application is using.
  3. Review IAM Policies: Verify that the IAM permissions associated with your AWS credentials are correctly configured to allow access to the S3 bucket.

Example Code

Let’s explore some code snippets to illustrate how to correctly configure and use AWS Polly with S3.

Setting Up AWS SDK for Java

Ensure that you have the AWS SDK for Java configured in your project. You can add the dependency in your Maven pom.xml:

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<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-polly</artifactId>
    <version>1.12.300</version>
</dependency>
<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-s3</artifactId>
    <version>1.12.300</version>
</dependency>

Example: Creating Speech and Storing in S3

Here’s how to create speech and store the audio file in S3:

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import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.polly.AmazonPolly;
import com.amazonaws.services.polly.AmazonPollyClientBuilder;
import com.amazonaws.services.polly.model.*;

public class PollyExample {
    
    public static void main(String[] args) {
        // Initialize AWS credentials
        BasicAWSCredentials awsCredentials = new BasicAWSCredentials("YOUR_ACCESS_KEY", "YOUR_SECRET_KEY");
        
        // Create an Amazon Polly Client
        AmazonPolly polly = AmazonPollyClientBuilder.standard()
                .withCredentials(new AWSStaticCredentialsProvider(awsCredentials))
                .withRegion(Regions.US_EAST_1)
                .build();
        
        // Create the SynthesizeSpeechRequest
        SynthesizeSpeechRequest request = new SynthesizeSpeechRequest()
                .withText("Hello World")
                .withVoiceId("Joanna") // You can choose other voices as well
                .withOutputFormat(OutputFormat.Mp3)
                .withS3BucketName("YOUR_BUCKET_NAME") // Make sure this bucket exists
                .withS3Key("audio/hello_world.mp3");

        // Request to synthesize speech
        try {
            SynthesizeSpeechResult result = polly.synthesizeSpeech(request);

            // Handle the audio output from result
            // More code to store to S3 can be implemented here.

        } catch (InvalidS3KeyException e) {
            System.out.println("Invalid S3 Key: " + e.getMessage());
        } catch (Exception e) {
            System.out.println("Error: " + e.getMessage());
        }
    }
}

Steps to Debug the Exception

  1. Log the Exception Message: Always log the message when catching the InvalidS3KeyException to gain insights about what went wrong.

  2. Verify the S3 Key and Bucket: Double-check the values provided in the withS3BucketName and withS3Key methods.

  3. Use the AWS Console: Go to the AWS S3 console and verify that the file indeed exists in the specified path.

  4. IAM Policy Example: Ensure your IAM policy has the necessary permissions to access the S3 bucket:

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{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:GetObject",
                "s3:PutObject"
            ],
            "Resource": "arn:aws:s3:::YOUR_BUCKET_NAME/*"
        }
    ]
}

Conclusion

The InvalidS3KeyException in AWS Polly can be frustrating, but with the right debugging steps, it is a resolvable issue. Make sure to check your S3 keys meticulously, review bucket permissions, and configure your IAM policies adequately. Following the practices outlined in this article will help you ensure a smooth experience when working with AWS Polly and S3.

By implementing these best practices, you will not only resolve the InvalidS3KeyException but also enhance the overall robustness of your AWS applications.

References

AWS, AWS Polly
aws polly com.amazonaws.services.polly.model
This post is licensed under CC BY 4.0 by the author.