Amazon S3 examples using SDK for Swift - AWS SDK for Swift
BasicsActions

Amazon S3 examples using SDK for Swift

The following code examples show you how to perform actions and implement common scenarios by using the AWS SDK for Swift with Amazon S3.

Basics are code examples that show you how to perform the essential operations within a service.

Actions are code excerpts from larger programs and must be run in context. While actions show you how to call individual service functions, you can see actions in context in their related scenarios.

Each example includes a link to the complete source code, where you can find instructions on how to set up and run the code in context.

Basics

The following code example shows how to:

  • Create a bucket and upload a file to it.

  • Download an object from a bucket.

  • Copy an object to a subfolder in a bucket.

  • List the objects in a bucket.

  • Delete the bucket objects and the bucket.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

import Foundation
import AWSS3
import Smithy
import ClientRuntime

/// A class containing all the code that interacts with the AWS SDK for Swift.
public class ServiceHandler {
    let configuration: S3Client.S3ClientConfiguration
    let client: S3Client

    enum HandlerError: Error {
        case getObjectBody(String)
        case readGetObjectBody(String)
        case missingContents(String)
    }

    /// Initialize and return a new ``ServiceHandler`` object, which is used to drive the AWS calls
    /// used for the example.
    ///
    /// - Returns: A new ``ServiceHandler`` object, ready to be called to
    ///            execute AWS operations.
    public init() async throws {
        do {
            configuration = try await S3Client.S3ClientConfiguration() 
         //   configuration.region = "us-east-2" // Uncomment this to set the region programmatically.
            client = S3Client(config: configuration)
        }
        catch {
            print("ERROR: ", dump(error, name: "Initializing S3 client"))
            throw error
        }
    }


    /// Create a new user given the specified name.
    ///
    /// - Parameters:
    ///   - name: Name of the bucket to create.
    /// Throws an exception if an error occurs.
    public func createBucket(name: String) async throws {
        var input = CreateBucketInput(
            bucket: name
        )
        
        // For regions other than "us-east-1", you must set the locationConstraint in the createBucketConfiguration.
        // For more information, see LocationConstraint in the S3 API guide.
        // https://docs.aws.amazon.com/AmazonS3/latest/API/API_CreateBucket.html#API_CreateBucket_RequestBody
        if let region = configuration.region {
            if region != "us-east-1" {
                input.createBucketConfiguration = S3ClientTypes.CreateBucketConfiguration(locationConstraint: S3ClientTypes.BucketLocationConstraint(rawValue: region))
            }
        }

        do {
            _ = try await client.createBucket(input: input)
        }
        catch let error as BucketAlreadyOwnedByYou {
            print("The bucket '\(name)' already exists and is owned by you. You may wish to ignore this exception.")
            throw error
        }
        catch {
            print("ERROR: ", dump(error, name: "Creating a bucket"))
            throw error
        }
    }

    /// Delete a bucket.
    /// - Parameter name: Name of the bucket to delete.
    public func deleteBucket(name: String) async throws {
        let input = DeleteBucketInput(
            bucket: name
        )
        do {
            _ = try await client.deleteBucket(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Deleting a bucket"))
            throw error
        }
    }

    /// Upload a file from local storage to the bucket.
    /// - Parameters:
    ///   - bucket: Name of the bucket to upload the file to.
    ///   - key: Name of the file to create.
    ///   - file: Path name of the file to upload.
    public func uploadFile(bucket: String, key: String, file: String) async throws {
        let fileUrl = URL(fileURLWithPath: file)
        do {
            let fileData = try Data(contentsOf: fileUrl)
            let dataStream = ByteStream.data(fileData)

            let input = PutObjectInput(
                body: dataStream,
                bucket: bucket,
                key: key
            )

            _ = try await client.putObject(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Putting an object."))
            throw error
        }
    }

    /// Create a file in the specified bucket with the given name. The new
    /// file's contents are uploaded from a `Data` object.
    ///
    /// - Parameters:
    ///   - bucket: Name of the bucket to create a file in.
    ///   - key: Name of the file to create.
    ///   - data: A `Data` object to write into the new file.
    public func createFile(bucket: String, key: String, withData data: Data) async throws {
        let dataStream = ByteStream.data(data)

        let input = PutObjectInput(
            body: dataStream,
            bucket: bucket,
            key: key
        )

        do {
            _ = try await client.putObject(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Putting an object."))
            throw error
        }
    }

    /// Download the named file to the given directory on the local device.
    ///
    /// - Parameters:
    ///   - bucket: Name of the bucket that contains the file to be copied.
    ///   - key: The name of the file to copy from the bucket.
    ///   - to: The path of the directory on the local device where you want to
    ///     download the file.
    public func downloadFile(bucket: String, key: String, to: String) async throws {
        let fileUrl = URL(fileURLWithPath: to).appendingPathComponent(key)

        let input = GetObjectInput(
            bucket: bucket,
            key: key
        )
        do {
            let output = try await client.getObject(input: input)

            guard let body = output.body else {
                throw HandlerError.getObjectBody("GetObjectInput missing body.")
            }

            guard let data = try await body.readData() else {
                throw HandlerError.readGetObjectBody("GetObjectInput unable to read data.")
            }

            try data.write(to: fileUrl)
        }
        catch {
            print("ERROR: ", dump(error, name: "Downloading a file."))
            throw error
        }
    }

    /// Read the specified file from the given S3 bucket into a Swift
    /// `Data` object.
    ///
    /// - Parameters:
    ///   - bucket: Name of the bucket containing the file to read.
    ///   - key: Name of the file within the bucket to read.
    ///
    /// - Returns: A `Data` object containing the complete file data.
    public func readFile(bucket: String, key: String) async throws -> Data {
        let input = GetObjectInput(
            bucket: bucket,
            key: key
        )
        do {
            let output = try await client.getObject(input: input)
            
            guard let body = output.body else {
                throw HandlerError.getObjectBody("GetObjectInput missing body.")
            }

            guard let data = try await body.readData() else {
                throw HandlerError.readGetObjectBody("GetObjectInput unable to read data.")
            }

            return data
        }
        catch {
            print("ERROR: ", dump(error, name: "Reading a file."))
            throw error
        }
   }


    /// Copy a file from one bucket to another.
    ///
    /// - Parameters:
    ///   - sourceBucket: Name of the bucket containing the source file.
    ///   - name: Name of the source file.
    ///   - destBucket: Name of the bucket to copy the file into.
    public func copyFile(from sourceBucket: String, name: String, to destBucket: String) async throws {
        let srcUrl = ("\(sourceBucket)/\(name)").addingPercentEncoding(withAllowedCharacters: .urlPathAllowed)

        let input = CopyObjectInput(
            bucket: destBucket,
            copySource: srcUrl,
            key: name
        )
        do {
            _ = try await client.copyObject(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Copying an object."))
            throw error
        }
    }

    /// Deletes the specified file from Amazon S3.
    ///
    /// - Parameters:
    ///   - bucket: Name of the bucket containing the file to delete.
    ///   - key: Name of the file to delete.
    ///
    public func deleteFile(bucket: String, key: String) async throws {
        let input = DeleteObjectInput(
            bucket: bucket,
            key: key
        )

        do {
            _ = try await client.deleteObject(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Deleting a file."))
            throw error
        }
    }

    /// Returns an array of strings, each naming one file in the
    /// specified bucket.
    ///
    /// - Parameter bucket: Name of the bucket to get a file listing for.
    /// - Returns: An array of `String` objects, each giving the name of
    ///            one file contained in the bucket.
    public func listBucketFiles(bucket: String) async throws -> [String] {
        do {
            let input = ListObjectsV2Input(
                bucket: bucket
            )
            
            // Use "Paginated" to get all the objects.
            // This lets the SDK handle the 'continuationToken' in "ListObjectsV2Output".
            let output = client.listObjectsV2Paginated(input: input)
            var names: [String] = []
            
            for try await page in output {
                guard let objList = page.contents else {
                    print("ERROR: listObjectsV2Paginated returned nil contents.")
                    continue
                }
                
                for obj in objList {
                    if let objName = obj.key {
                        names.append(objName)
                    }
                }
            }
            
            
            return names
        }
        catch {
            print("ERROR: ", dump(error, name: "Listing objects."))
            throw error
        }
    }
}


import AWSS3

import Foundation
import ServiceHandler
import ArgumentParser

/// The command-line arguments and options available for this
/// example command.
struct ExampleCommand: ParsableCommand {
    @Argument(help: "Name of the S3 bucket to create")
    var bucketName: String

    @Argument(help: "Pathname of the file to upload to the S3 bucket")
    var uploadSource: String

    @Argument(help: "The name (key) to give the file in the S3 bucket")
    var objName: String

    @Argument(help: "S3 bucket to copy the object to")
    var destBucket: String

    @Argument(help: "Directory where you want to download the file from the S3 bucket")
    var downloadDir: String

    static var configuration = CommandConfiguration(
        commandName: "s3-basics",
        abstract: "Demonstrates a series of basic AWS S3 functions.",
        discussion: """
        Performs the following Amazon S3 commands:

        * `CreateBucket`
        * `PutObject`
        * `GetObject`
        * `CopyObject`
        * `ListObjects`
        * `DeleteObjects`
        * `DeleteBucket`
        """
    )

    /// Called by ``main()`` to do the actual running of the AWS
    /// example.
    func runAsync() async throws {
        let serviceHandler = try await ServiceHandler()

        // 1. Create the bucket.
        print("Creating the bucket \(bucketName)...")
        try await serviceHandler.createBucket(name: bucketName)

        // 2. Upload a file to the bucket.
        print("Uploading the file \(uploadSource)...")
        try await serviceHandler.uploadFile(bucket: bucketName, key: objName, file: uploadSource)

        // 3. Download the file.
        print("Downloading the file \(objName) to \(downloadDir)...")
        try await serviceHandler.downloadFile(bucket: bucketName, key: objName, to: downloadDir)

        // 4. Copy the file to another bucket.
        print("Copying the file to the bucket \(destBucket)...")
        try await serviceHandler.copyFile(from: bucketName, name: objName, to: destBucket)

        // 5. List the contents of the bucket.

        print("Getting a list of the files in the bucket \(bucketName)")
        let fileList = try await serviceHandler.listBucketFiles(bucket: bucketName)
        let numFiles = fileList.count
        if numFiles != 0 {
            print("\(numFiles) file\((numFiles > 1) ? "s" : "") in bucket \(bucketName):")
            for name in fileList {
                print("  \(name)")
            }
        } else {
            print("No files found in bucket \(bucketName)")
        }

        // 6. Delete the objects from the bucket.

        print("Deleting the file \(objName) from the bucket \(bucketName)...")
        try await serviceHandler.deleteFile(bucket: bucketName, key: objName)
        print("Deleting the file \(objName) from the bucket \(destBucket)...")
        try await serviceHandler.deleteFile(bucket: destBucket, key: objName)

        // 7. Delete the bucket.
        print("Deleting the bucket \(bucketName)...")
        try await serviceHandler.deleteBucket(name: bucketName)

        print("Done.")
    }
}

//
// Main program entry point.
//
@main
struct Main {
    static func main() async {
        let args = Array(CommandLine.arguments.dropFirst())

        do {
            let command = try ExampleCommand.parse(args)
            try await command.runAsync()
        } catch {
            ExampleCommand.exit(withError: error)
        }
    }    
}

Actions

The following code example shows how to use CopyObject.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

    public func copyFile(from sourceBucket: String, name: String, to destBucket: String) async throws {
        let srcUrl = ("\(sourceBucket)/\(name)").addingPercentEncoding(withAllowedCharacters: .urlPathAllowed)

        let input = CopyObjectInput(
            bucket: destBucket,
            copySource: srcUrl,
            key: name
        )
        do {
            _ = try await client.copyObject(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Copying an object."))
            throw error
        }
    }

  • For API details, see CopyObject in AWS SDK for Swift API reference.

The following code example shows how to use CreateBucket.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

    public func createBucket(name: String) async throws {
        var input = CreateBucketInput(
            bucket: name
        )
        
        // For regions other than "us-east-1", you must set the locationConstraint in the createBucketConfiguration.
        // For more information, see LocationConstraint in the S3 API guide.
        // https://docs.aws.amazon.com/AmazonS3/latest/API/API_CreateBucket.html#API_CreateBucket_RequestBody
        if let region = configuration.region {
            if region != "us-east-1" {
                input.createBucketConfiguration = S3ClientTypes.CreateBucketConfiguration(locationConstraint: S3ClientTypes.BucketLocationConstraint(rawValue: region))
            }
        }

        do {
            _ = try await client.createBucket(input: input)
        }
        catch let error as BucketAlreadyOwnedByYou {
            print("The bucket '\(name)' already exists and is owned by you. You may wish to ignore this exception.")
            throw error
        }
        catch {
            print("ERROR: ", dump(error, name: "Creating a bucket"))
            throw error
        }
    }

  • For API details, see CreateBucket in AWS SDK for Swift API reference.

The following code example shows how to use DeleteBucket.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

    public func deleteBucket(name: String) async throws {
        let input = DeleteBucketInput(
            bucket: name
        )
        do {
            _ = try await client.deleteBucket(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Deleting a bucket"))
            throw error
        }
    }

  • For API details, see DeleteBucket in AWS SDK for Swift API reference.

The following code example shows how to use DeleteObject.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

    public func deleteFile(bucket: String, key: String) async throws {
        let input = DeleteObjectInput(
            bucket: bucket,
            key: key
        )

        do {
            _ = try await client.deleteObject(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Deleting a file."))
            throw error
        }
    }

  • For API details, see DeleteObject in AWS SDK for Swift API reference.

The following code example shows how to use DeleteObjects.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

    public func deleteObjects(bucket: String, keys: [String]) async throws {
        let input = DeleteObjectsInput(
            bucket: bucket,
            delete: S3ClientTypes.Delete(
                objects: keys.map { S3ClientTypes.ObjectIdentifier(key: $0) },
                quiet: true
            )
        )

        do {
            _ = try await client.deleteObjects(input: input)
        } catch {
            print("ERROR: deleteObjects:", dump(error))
            throw error
        }
    }

  • For API details, see DeleteObjects in AWS SDK for Swift API reference.

The following code example shows how to use GetObject.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

    public func downloadFile(bucket: String, key: String, to: String) async throws {
        let fileUrl = URL(fileURLWithPath: to).appendingPathComponent(key)

        let input = GetObjectInput(
            bucket: bucket,
            key: key
        )
        do {
            let output = try await client.getObject(input: input)

            guard let body = output.body else {
                throw HandlerError.getObjectBody("GetObjectInput missing body.")
            }

            guard let data = try await body.readData() else {
                throw HandlerError.readGetObjectBody("GetObjectInput unable to read data.")
            }

            try data.write(to: fileUrl)
        }
        catch {
            print("ERROR: ", dump(error, name: "Downloading a file."))
            throw error
        }
    }


import AWSS3

    public func readFile(bucket: String, key: String) async throws -> Data {
        let input = GetObjectInput(
            bucket: bucket,
            key: key
        )
        do {
            let output = try await client.getObject(input: input)
            
            guard let body = output.body else {
                throw HandlerError.getObjectBody("GetObjectInput missing body.")
            }

            guard let data = try await body.readData() else {
                throw HandlerError.readGetObjectBody("GetObjectInput unable to read data.")
            }

            return data
        }
        catch {
            print("ERROR: ", dump(error, name: "Reading a file."))
            throw error
        }
   }

  • For API details, see GetObject in AWS SDK for Swift API reference.

The following code example shows how to use ListBuckets.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

    /// Return an array containing information about every available bucket.
    ///
    /// - Returns: An array of ``S3ClientTypes.Bucket`` objects describing
    ///   each bucket.
    public func getAllBuckets() async throws -> [S3ClientTypes.Bucket] {
        return try await client.listBuckets(input: ListBucketsInput())
    }

  • For API details, see ListBuckets in AWS SDK for Swift API reference.

The following code example shows how to use ListObjectsV2.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3

    public func listBucketFiles(bucket: String) async throws -> [String] {
        do {
            let input = ListObjectsV2Input(
                bucket: bucket
            )
            
            // Use "Paginated" to get all the objects.
            // This lets the SDK handle the 'continuationToken' in "ListObjectsV2Output".
            let output = client.listObjectsV2Paginated(input: input)
            var names: [String] = []
            
            for try await page in output {
                guard let objList = page.contents else {
                    print("ERROR: listObjectsV2Paginated returned nil contents.")
                    continue
                }
                
                for obj in objList {
                    if let objName = obj.key {
                        names.append(objName)
                    }
                }
            }
            
            
            return names
        }
        catch {
            print("ERROR: ", dump(error, name: "Listing objects."))
            throw error
        }
    }

  • For API details, see ListObjectsV2 in AWS SDK for Swift API reference.

The following code example shows how to use PutObject.

SDK for Swift
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the AWS Code Examples Repository. 

import AWSS3
import Smithy

    public func uploadFile(bucket: String, key: String, file: String) async throws {
        let fileUrl = URL(fileURLWithPath: file)
        do {
            let fileData = try Data(contentsOf: fileUrl)
            let dataStream = ByteStream.data(fileData)

            let input = PutObjectInput(
                body: dataStream,
                bucket: bucket,
                key: key
            )

            _ = try await client.putObject(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Putting an object."))
            throw error
        }
    }


import AWSS3
import Smithy

    public func createFile(bucket: String, key: String, withData data: Data) async throws {
        let dataStream = ByteStream.data(data)

        let input = PutObjectInput(
            body: dataStream,
            bucket: bucket,
            key: key
        )

        do {
            _ = try await client.putObject(input: input)
        }
        catch {
            print("ERROR: ", dump(error, name: "Putting an object."))
            throw error
        }
    }

  • For API details, see PutObject in AWS SDK for Swift API reference.