amazon s3 iphone sdk 下载图片

Question

在我的一生中，我无法弄清楚如何在我的 iOS 项目中实现亚马逊的 sdk，而且我似乎找不到太多关于我正在尝试做什么的文档......希望你能提供帮助！

我想非常简单地从我的 Amazon S3 帐户下载文件并将它们本地存储在 iPhone 上...我可以通过 http 地址访问图像来做到这一点，但这并不能像我一样保护图像更喜欢。

根据我的阅读，我应该这样做：

AmazonS3Client *s3Client = [[AmazonS3Client alloc] initWithAccessKey:@"mykey" withSecretKey:@"mysecretkey"];

        S3GetObjectRequest *requestedObject = [[S3GetObjectRequest alloc] initWithKey:bucketPath withBucket:@"mybucket"];

        NSLog(@"requestedobject:%@", requestedObject - I get the log here);

        S3GetObjectResponse *getObjectResponse = [s3Client getObject:requestedObject];

        NSLog(@"requestedobject2:%@", getObjectResponse - it crashes before this happens);
        NSData *myData2;
        myData2 = getObjectResponse.body;
        [myData2 writeToFile:bucketPath atomically:YES];

我显然在 getObjectResponse、getObject 代码上做错了，但我不知道正确的语法...任何帮助将不胜感激！

这是日志： 2012-08-02 17:12:33.856 收藏大师版[13176:4e07] 请求对象： 2012-08-02 17:12:34.044 Collection Master Edition[13176:4e07] * 由于未捕获的异常“AmazonServiceException”而终止应用程序，原因：“（null）”

也许我还应该提到我可以使用以下代码获取存储桶列表内容

 S3ListObjectsRequest *listObjectRequest = [[S3ListObjectsRequest alloc] initWithName:@"my bucket"];

        S3ListObjectsResponse *listObjectResponse = [s3Client listObjects:listObjectRequest];

        S3ListObjectsResult *listObjectsResults = listObjectResponse.listObjectsResult;

        for (S3ObjectSummary *objectSummary in listObjectsResults.objectSummaries) {

            NSLog(@"Bucket Contents:%@" ,[objectSummary key]); // This returns the contents of the bucket

        }

谢谢！ 扎克

Answer 1

从我在这里看到的情况来看，您可能会遇到两个问题之一。我第一次开始使用 AWS 时遇到了类似的问题。首先确保您的存储桶名称全部为小写字母。您应该通过将其放入 @try - @catch 块并记录错误来检查为什么会发生这种情况，这在解决您的问题时提供了非常详细的信息。

    -(UIImage *)getImageFromS3{      


    @try{
    AmazonS3Client *_s3Client = [[AmazonS3Client alloc]initWithAccessKey:ACCESS_KEY withSecretKey:SECRET_KEY];      

    S3GetObjectRequest *getObjectRequest = [[S3GetObjectRequest alloc]initWithKey:imageKey withBucket:pictureBucket];

  S3GetObjectResponse *response = [_s3Client getObject:getObjectRequest];

    if (response.error == nil)
    {
        if (response.body != nil)
        {
        UIImage *someImage = [UIImage imageWithData:reponse.body];
    return someImage;
        }
        else{
            NSLog(@"There was no value in the response body");
            return nil;
             }
    }
    else if (response.error != nil)
    {
        NSLog(@"There was an error in the response while getting image: %@",response.error.description);
    }
}

    @catch (NSException *exception) {
    NSLog(@"There was an exception when connecting to s3: %@",exception.description);
}

} 

Answer 2

问题可能是与您的密钥对关联的权限。我的建议是去你的IAM on your Management Console 并创建一个具有你想要的适当 S3 权限的新组，在这种情况下几乎所有这些权限，除了一些你不需要的更多管理的东西（所以主要只是 POST，GET权限）。然后在该组中创建一个用户并使用该密钥对进行测试。这可能会让事情变得清晰，因为这是我认为对我有用的过程。貌似列表权限比较低，但是POST和GET需要不同的权限。

Answer 3

可能是允许的，但可能会帮助某些人。这是在amazone-s3中上传图片的代码

constant.h
#import <Foundation/Foundation.h>
#define SECRET_KEY             @"your secret kry"
#define ACCESS_KEY_ID          @"your access id"

#define PICTURE_BUCKET @"桶名" #define PICTURE_NAME @"任何单词" #define CREDENTIALS_ERROR_TITLE @"缺少凭据" #define CREDENTIALS_ERROR_MESSAGE @"AWS 凭证配置不正确。请查看 README 文件。"

@interface 常量：NSObject

+(NSString *)pictureBucket;

@结束

在常量.m中

#import "Constant.h"

@implementation 常量 +(NSString *)图片桶 { return [[NSString stringWithFormat:@"%@-%@", PICTURE_BUCKET, ACCESS_KEY_ID] lowercaseString]; }

@end

在 UploadViewController.h 中

  typedef enum {
  GrandCentralDispatch,
  Delegate,
  BackgroundThread
  } UploadType;

  @interface UploadPhotoViewController :  UIViewController<UIImagePickerControllerDelegate,UINavigationControllerDelegate,UINavigationControllerDelegate, AmazonServiceRequestDelegate>
 {
UploadType _uploadType;
 }

 @property (strong, nonatomic) IBOutlet UIButton *buttonSelectPhoto;
  @property (nonatomic, retain) AmazonS3Client *s3;

在 UploadViewController.m 中

      #import "UploadPhotoViewController.h"
       #import <AWSRuntime/AWSRuntime.h>
      #import "Constant.h"

       @interface UploadPhotoViewController ()

        @end

         @implementation UploadPhotoViewController

     - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
        {
     self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
    // Custom initialization
      }
       return self;
     }

       - (void)viewDidLoad
      {
     [super viewDidLoad];
// Do any additional setup after loading the view from its nib.

     #ifdef DEBUG
     [AmazonLogger verboseLogging];
   #else
      [AmazonLogger turnLoggingOff];
   #endif

     [AmazonErrorHandler shouldNotThrowExceptions];

      if(![ACCESS_KEY_ID isEqualToString:@"CHANGE ME"]
          && self.s3 == nil)
       {
    // Initial the S3 Client.
    //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    // This sample App is for demonstration purposes only.
    // It is not secure to embed your credentials into source code.
    // DO NOT EMBED YOUR CREDENTIALS IN PRODUCTION APPS.
    // We offer two solutions for getting credentials to your mobile App.
    // Please read the following article to learn about Token Vending Machine:
    // * http://aws.amazon.com/articles/Mobile/4611615499399490
    // Or consider using web identity federation:
    // * http://aws.amazon.com/articles/Mobile/4617974389850313
    //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    self.s3 = [[AmazonS3Client alloc] initWithAccessKey:ACCESS_KEY_ID withSecretKey:SECRET_KEY] ;
    self.s3.endpoint = [AmazonEndpoints s3Endpoint:US_WEST_2];

    // Create the picture bucket.
    S3CreateBucketRequest *createBucketRequest = [[S3CreateBucketRequest alloc] initWithName:[Constant pictureBucket] andRegion:[S3Region USWest2]];
    S3CreateBucketResponse *createBucketResponse = [self.s3 createBucket:createBucketRequest];
    if(createBucketResponse.error != nil)
    {
        NSLog(@"Error: %@", createBucketResponse.error);
    }
}

  }
   -(void)viewDidAppear:(BOOL)animated
 {
[super viewDidAppear:animated];

if ([ACCESS_KEY_ID isEqualToString:@"CHANGE ME"])
{
    [self showAlertMessage:CREDENTIALS_ERROR_MESSAGE withTitle:CREDENTIALS_ERROR_TITLE];
}

} - (void)showAlertMessage:(NSString *)message withTitle:(NSString *)title { UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:title 消息：消息 代表：无 取消按钮标题：@“确定” 其他按钮标题：无]； alertView.delegate=self; [警报视图显示]； } - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{

    // Set the content type so that the browser will treat the URL as an image.
    S3ResponseHeaderOverrides *override = [[S3ResponseHeaderOverrides alloc] init];
    override.contentType = @"image/jpeg";

    // Request a pre-signed URL to picture that has been uplaoded.
    S3GetPreSignedURLRequest *gpsur = [[S3GetPreSignedURLRequest alloc] init];
    gpsur.key                     = PICTURE_NAME;
    gpsur.bucket                  = [Constant pictureBucket];
    gpsur.expires                 = [NSDate dateWithTimeIntervalSinceNow:(NSTimeInterval) 3600]; // Added an hour's worth of seconds to the current time.
    gpsur.responseHeaderOverrides = override;

    // Get the URL
    NSError *error = nil;
    NSURL *url = [self.s3 getPreSignedURL:gpsur error:&error];

    if(url == nil)
    {
        if(error != nil)
        {
            dispatch_async(dispatch_get_main_queue(), ^{

                NSLog(@"Error: %@", error);
                [self showAlertMessage:[error.userInfo objectForKey:@"message"] withTitle:@"Browser Error"];
            });
        }
    }
    else
    {
        /*dispatch_async(dispatch_get_main_queue(), ^{
            // Display the URL in Safari
            [[UIApplication sharedApplication] openURL:url];

        });*/
    }NSLog(@"url is %@",url);

});

 }

   - (void)didReceiveMemoryWarning
   {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
  }

   - (IBAction)buttonTakePhoto:(id)sender
   {
UIImagePickerController *picker = [[UIImagePickerController alloc] init];

picker.delegate = self;

picker.allowsEditing = YES;

picker.sourceType = UIImagePickerControllerSourceTypeCamera;



[self presentViewController:picker animated:YES completion:NULL];
  }

   - (IBAction)buttonSelectPhoto:(id)sender
   {
 [self showImagePicker:Delegate];
 }

    - (void)showImagePicker:(UploadType)uploadType
{
UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init] ;
imagePicker.delegate = self;

_uploadType = uploadType;

[self presentViewController:imagePicker animated:YES completion:NULL];
   }


  - (void)processDelegateUpload:(NSData *)imageData
 {
// Upload image data.  Remember to set the content type.
S3PutObjectRequest *por = [[S3PutObjectRequest alloc] initWithKey:PICTURE_NAME
                                                          inBucket:[Constant pictureBucket]];
por.contentType = @"image/jpeg";
por.data = imageData;
por.delegate = self;

// Put the image data into the specified s3 bucket and object.
[self.s3 putObject:por];
 }

     -(void)request:(AmazonServiceRequest *)request didCompleteWithResponse:(AmazonServiceResponse *)response
  {
[self showAlertMessage:@"The image was successfully uploaded." withTitle:@"Upload Completed"];

[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
  }

 -(void)request:(AmazonServiceRequest *)request didFailWithError:(NSError *)error
  {
NSLog(@"Error: %@", error);
[self showAlertMessage:error.description withTitle:@"Upload Error"];

[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
  }

   #pragma mark - UIImagePickerControllerDelegate methods

       -(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
    {
// Get the selected image.
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];

// Convert the image to JPEG data.
NSData *imageData = UIImageJPEGRepresentation(image, 1.0);


if(_uploadType == Delegate)
{
    [self processDelegateUpload:imageData];
}

[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];

[picker dismissViewControllerAnimated:YES completion:NULL];
   }

   -(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
  {
[picker dismissViewControllerAnimated:YES completion:NULL];
   }

     - (IBAction)buttonBack:(id)sender
     {
[self.navigationController popViewControllerAnimated:YES];
   }

   @end