Swift - AWS S3从照片库上传图片并下载它

Question

我查看了许多亚马逊文档，但没有找到足够的信息来上传和下载图像到S3使用Swift。
我该怎么做？

Answer 1

做很多研究，我已经得到了这个工作后，

import AWSS3 
import AWSCore 

上传：

我假定你已经实现UIImagePickerControllerDelegate了。

第1步：

• 举行URL创建变量：

  var imageURL = NSURL() 
  

• 创建上传完成处理的obj：

  var uploadCompletionHandler: AWSS3TransferUtilityUploadCompletionHandlerBlock? 
  

步骤2：从imagePickerController(_:didFinishPickingMediaWithInfo:)获取图像URL：

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]){ 

    //getting details of image 
    let uploadFileURL = info[UIImagePickerControllerReferenceURL] as! NSURL 

    let imageName = uploadFileURL.lastPathComponent 
    let documentDirectory = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first! as String 

    // getting local path 
    let localPath = (documentDirectory as NSString).stringByAppendingPathComponent(imageName!) 


    //getting actual image 
    let image = info[UIImagePickerControllerOriginalImage] as! UIImage 
    let data = UIImagePNGRepresentation(image) 
    data!.writeToFile(localPath, atomically: true) 

    let imageData = NSData(contentsOfFile: localPath)! 
    imageURL = NSURL(fileURLWithPath: localPath) 

    picker.dismissViewControllerAnimated(true, completion: nil) 
} 

步骤3：：呼叫后imageURL集此uploadImage方法在此委托方法的imageURL

• 设定值将图片上传到您的存储区：

  func uploadImage(){ 
  
      //defining bucket and upload file name 
      let S3BucketName: String = "bucketName" 
      let S3UploadKeyName: String = "public/testImage.jpg" 
  
  
      let expression = AWSS3TransferUtilityUploadExpression() 
      expression.uploadProgress = {(task: AWSS3TransferUtilityTask, bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) in 
       dispatch_async(dispatch_get_main_queue(), { 
        let progress = Float(totalBytesSent)/Float(totalBytesExpectedToSend) 
        print("Progress is: \(progress)") 
       }) 
      } 
  
      self.uploadCompletionHandler = { (task, error) -> Void in 
       dispatch_async(dispatch_get_main_queue(), { 
        if ((error) != nil){ 
         print("Failed with error") 
         print("Error: \(error!)"); 
        } 
        else{ 
         print("Sucess") 
        } 
       }) 
      } 
  
      let transferUtility = AWSS3TransferUtility.defaultS3TransferUtility() 
  
      transferUtility.uploadFile(imageURL, bucket: S3BucketName, key: S3UploadKeyName, contentType: "image/jpeg", expression: expression, completionHander: uploadCompletionHandler).continueWithBlock { (task) -> AnyObject! in 
       if let error = task.error { 
        print("Error: \(error.localizedDescription)") 
       } 
       if let exception = task.exception { 
        print("Exception: \(exception.description)") 
       } 
       if let _ = task.result { 
        print("Upload Starting!") 
       } 
  
       return nil; 
      } 
  } 
  

  下载：

  func downloadImage(){ 
  
      var completionHandler: AWSS3TransferUtilityDownloadCompletionHandlerBlock? 
  
      let S3BucketName: String = "bucketName" 
      let S3DownloadKeyName: String = "public/testImage.jpg" 
  
      let expression = AWSS3TransferUtilityDownloadExpression() 
      expression.downloadProgress = {(task: AWSS3TransferUtilityTask, bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) in 
       dispatch_async(dispatch_get_main_queue(), { 
        let progress = Float(totalBytesSent)/Float(totalBytesExpectedToSend) 
        print("Progress is: \(progress)") 
       }) 
      } 
  
      completionHandler = { (task, location, data, error) -> Void in 
       dispatch_async(dispatch_get_main_queue(), { 
        if ((error) != nil){ 
         print("Failed with error") 
         print("Error: \(error!)") 
        } 
        else{ 
         //Set your image 
         var downloadedImage = UIImage(data: data!) 
        } 
       }) 
      } 
  
      let transferUtility = AWSS3TransferUtility.defaultS3TransferUtility() 
  
      transferUtility.downloadToURL(nil, bucket: S3BucketName, key: S3DownloadKeyName, expression: expression, completionHander: completionHandler).continueWithBlock { (task) -> AnyObject! in 
       if let error = task.error { 
        print("Error: \(error.localizedDescription)") 
       } 
       if let exception = task.exception { 
        print("Exception: \(exception.description)") 
       } 
       if let _ = task.result { 
        print("Download Starting!") 
       } 
       return nil; 
      } 
  
  } 
  

  Ref. for upload image

  Ref. for download image

  非常感谢jzorz

Answer 2

如果你想要的是下载的图片，这是一个更简洁正确的方法：

func downloadImage(bucketName: String, fileName: String, completion: (image: UIImage?, error: NSError?) -> Void) { 
    let transferUtility = AWSS3TransferUtility.defaultS3TransferUtility() 

    transferUtility.downloadDataFromBucket(bucketName, key: fileName, expression: nil) { (task, url, data, error) in 
     var resultImage: UIImage? 

     if let data = data { 
      resultImage = UIImage(data: data) 
     } 

     completion(image: resultImage, error: error) 
    } 
}