# Upload a stream of unknown size to an Amazon S3 object using an AWS SDK
<a name="s3_example_s3_Scenario_UploadStream_section"></a>

The following code examples show how to upload a stream of unknown size to an Amazon S3 object.

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/s3#code-examples). 
Use the [AWS CRT-based S3 Client](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/crt-based-s3-client.html).  

```
import com.example.s3.util.AsyncExampleUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.core.async.AsyncRequestBody;
import software.amazon.awssdk.core.exception.SdkException;
import software.amazon.awssdk.services.s3.S3AsyncClient;
import software.amazon.awssdk.services.s3.model.PutObjectResponse;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class PutObjectFromStreamAsync {
    private static final Logger logger = LoggerFactory.getLogger(PutObjectFromStreamAsync.class);

    public static void main(String[] args) {
        String bucketName = "amzn-s3-demo-bucket-" + UUID.randomUUID(); // Change bucket name.
        String key = UUID.randomUUID().toString();

        AsyncExampleUtils.createBucket(bucketName);
        try {
            PutObjectFromStreamAsync example = new PutObjectFromStreamAsync();
            S3AsyncClient s3AsyncClientCrt = S3AsyncClient.crtCreate();
            PutObjectResponse putObjectResponse = example.putObjectFromStreamCrt(s3AsyncClientCrt, bucketName, key);
            logger.info("Object {} etag: {}", key, putObjectResponse.eTag());
            logger.info("Object {} uploaded to bucket {}.", key, bucketName);
        } catch (SdkException e) {
            logger.error(e.getMessage(), e);
        } finally {
            AsyncExampleUtils.deleteObject(bucketName, key);
            AsyncExampleUtils.deleteBucket(bucketName);
        }
    }

    /**
     * @param s33CrtAsyncClient - To upload content from a stream of unknown size, use can the AWS CRT-based S3 client.
     * @param bucketName - The name of the bucket.
     * @param key - The name of the object.
     * @return software.amazon.awssdk.services.s3.model.PutObjectResponse - Returns metadata pertaining to the put object operation.
     */
    public PutObjectResponse putObjectFromStreamCrt(S3AsyncClient s33CrtAsyncClient, String bucketName, String key) {

        // AsyncExampleUtils.randomString() returns a random string up to 100 characters.
        String randomString = AsyncExampleUtils.randomString();
        logger.info("random string to upload: {}: length={}", randomString, randomString.length());
        InputStream inputStream = new ByteArrayInputStream(randomString.getBytes());

        // Executor required to handle reading from the InputStream on a separate thread so the main upload is not blocked.
        ExecutorService executor = Executors.newSingleThreadExecutor();
        // Specify `null` for the content length when you don't know the content length.
        AsyncRequestBody body = AsyncRequestBody.fromInputStream(inputStream, null, executor);

        CompletableFuture<PutObjectResponse> responseFuture =
                s33CrtAsyncClient.putObject(r -> r.bucket(bucketName).key(key), body);

        PutObjectResponse response = responseFuture.join(); // Wait for the response.
        logger.info("Object {} uploaded to bucket {}.", key, bucketName);
        executor.shutdown();
        return response;
    }
}
```
Use the standard [ asynchronous S3 client with multipart upload enabled](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/s3-async-client-multipart.html#s3-async-client-mp-on).  

```
import com.example.s3.util.AsyncExampleUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.core.async.AsyncRequestBody;
import software.amazon.awssdk.core.exception.SdkException;
import software.amazon.awssdk.services.s3.S3AsyncClient;
import software.amazon.awssdk.services.s3.model.PutObjectResponse;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class PutObjectFromStreamAsyncMp {
    private static final Logger logger = LoggerFactory.getLogger(PutObjectFromStreamAsyncMp.class);

    public static void main(String[] args) {
        String bucketName = "amzn-s3-demo-bucket-" + UUID.randomUUID(); // Change bucket name.
        String key = UUID.randomUUID().toString();

        AsyncExampleUtils.createBucket(bucketName);
        try {
            PutObjectFromStreamAsyncMp example = new PutObjectFromStreamAsyncMp();
            S3AsyncClient s3AsyncClientMp = S3AsyncClient.builder().multipartEnabled(true).build();
            PutObjectResponse putObjectResponse = example.putObjectFromStreamMp(s3AsyncClientMp, bucketName, key);
            logger.info("Object {} etag: {}", key, putObjectResponse.eTag());
            logger.info("Object {} uploaded to bucket {}.", key, bucketName);
        } catch (SdkException e) {
            logger.error(e.getMessage(), e);
        } finally {
            AsyncExampleUtils.deleteObject(bucketName, key);
            AsyncExampleUtils.deleteBucket(bucketName);
        }
    }

    /**
     * @param s3AsyncClientMp - To upload content from a stream of unknown size, use can the S3 asynchronous client with multipart enabled.
     * @param bucketName - The name of the bucket.
     * @param key - The name of the object.
     * @return software.amazon.awssdk.services.s3.model.PutObjectResponse - Returns metadata pertaining to the put object operation.
     */
    public PutObjectResponse putObjectFromStreamMp(S3AsyncClient s3AsyncClientMp, String bucketName, String key) {

        // AsyncExampleUtils.randomString() returns a random string up to 100 characters.
        String randomString = AsyncExampleUtils.randomString();
        logger.info("random string to upload: {}: length={}", randomString, randomString.length());
        InputStream inputStream = new ByteArrayInputStream(randomString.getBytes());

        // Executor required to handle reading from the InputStream on a separate thread so the main upload is not blocked.
        ExecutorService executor = Executors.newSingleThreadExecutor();
        // Specify `null` for the content length when you don't know the content length.
        AsyncRequestBody body = AsyncRequestBody.fromInputStream(inputStream, null, executor);

        CompletableFuture<PutObjectResponse> responseFuture =
                s3AsyncClientMp.putObject(r -> r.bucket(bucketName).key(key), body);

        PutObjectResponse response = responseFuture.join(); // Wait for the response.
        logger.info("Object {} uploaded to bucket {}.", key, bucketName);
        executor.shutdown();
        return response;
    }
}
```
Use the [Amazon S3 Transfer Manager](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/transfer-manager.html).  

```
import com.example.s3.util.AsyncExampleUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import software.amazon.awssdk.core.async.AsyncRequestBody;
import software.amazon.awssdk.core.exception.SdkException;
import software.amazon.awssdk.transfer.s3.S3TransferManager;
import software.amazon.awssdk.transfer.s3.model.CompletedUpload;
import software.amazon.awssdk.transfer.s3.model.Upload;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.UUID;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class UploadStream {
    private static final Logger logger = LoggerFactory.getLogger(UploadStream.class);

    public static void main(String[] args) {
        String bucketName = "amzn-s3-demo-bucket" + UUID.randomUUID();
        String key = UUID.randomUUID().toString();

        AsyncExampleUtils.createBucket(bucketName);
        try {
            UploadStream example = new UploadStream();
            CompletedUpload completedUpload = example.uploadStream(S3TransferManager.create(), bucketName, key);
            logger.info("Object {} etag: {}", key, completedUpload.response().eTag());
            logger.info("Object {} uploaded to bucket {}.", key, bucketName);
        } catch (SdkException e) {
            logger.error(e.getMessage(), e);
        } finally {
            AsyncExampleUtils.deleteObject(bucketName, key);
            AsyncExampleUtils.deleteBucket(bucketName);
        }
    }

    /**
     * @param transferManager - To upload content from a stream of unknown size, you can use the S3TransferManager based on the AWS CRT-based S3 client.
     * @param bucketName - The name of the bucket.
     * @param key - The name of the object.
     * @return - software.amazon.awssdk.transfer.s3.model.CompletedUpload - The result of the completed upload.
     */
    public CompletedUpload uploadStream(S3TransferManager transferManager, String bucketName, String key) {

        // AsyncExampleUtils.randomString() returns a random string up to 100 characters.
        String randomString = AsyncExampleUtils.randomString();
        logger.info("random string to upload: {}: length={}", randomString, randomString.length());
        InputStream inputStream = new ByteArrayInputStream(randomString.getBytes());

        // Executor required to handle reading from the InputStream on a separate thread so the main upload is not blocked.
        ExecutorService executor = Executors.newSingleThreadExecutor();
        // Specify `null` for the content length when you don't know the content length.
        AsyncRequestBody body = AsyncRequestBody.fromInputStream(inputStream, null, executor);

        Upload upload = transferManager.upload(builder -> builder
                .requestBody(body)
                .putObjectRequest(req -> req.bucket(bucketName).key(key))
                .build());

        CompletedUpload completedUpload = upload.completionFuture().join();
        executor.shutdown();
        return completedUpload;
    }
}
```

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/s3/binary-streaming#code-examples). 

```
import ArgumentParser
import AWSClientRuntime
import AWSS3
import Foundation
import Smithy
import SmithyHTTPAPI
import SmithyStreams


    /// Upload a file to the specified bucket.
    ///
    /// - Parameters:
    ///   - bucket: The Amazon S3 bucket name to store the file into.
    ///   - key: The name (or path) of the file to upload to in the `bucket`.
    ///   - sourcePath: The pathname on the local filesystem of the file to
    ///     upload.
    func uploadFile(sourcePath: String, bucket: String, key: String?) async throws {
        let fileURL: URL = URL(fileURLWithPath: sourcePath)
        let fileName: String

        // If no key was provided, use the last component of the filename.
        
        if key == nil {
            fileName = fileURL.lastPathComponent
        } else {
            fileName = key!
        }
                
        let s3Client = try await S3Client()

        // Create a FileHandle for the source file.

        let fileHandle = FileHandle(forReadingAtPath: sourcePath)
        guard let fileHandle = fileHandle else {
            throw TransferError.readError
        }

        // Create a byte stream to retrieve the file's contents. This uses the
        // Smithy FileStream and ByteStream types.

        let stream = FileStream(fileHandle: fileHandle)
        let body = ByteStream.stream(stream)

        // Create a `PutObjectInput` with the ByteStream as the body of the
        // request's data. The AWS SDK for Swift will handle sending the
        // entire file in chunks, regardless of its size.
        
        let putInput = PutObjectInput(
            body: body,
            bucket: bucket,
            key: fileName
        )

        do {
            _ = try await s3Client.putObject(input: putInput)
        } catch {
            throw TransferError.uploadError("Error uploading the file: \(error)")
        }

        print("File uploaded to \(fileURL.path).")
    }
```

------

For a complete list of AWS SDK developer guides and code examples, see [Developing with Amazon S3 using the AWS SDKs](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.