无法替换Amazon S3存储桶中的文件

Question

无法替换Amazon S3存储桶中的文件

当我要将图像上传到amazon s3存储桶时，它显示如下错误： An item with the same key has already been added 。

我已经上传了一个图像文件，我想在需要时替换该图像。 但这是不允许的。

我该如何解决？

我正在使用C＃

 using (s3Client = Amazon.AWSClientFactory.CreateAmazonS3Client("key",   "secret key", Amazon.RegionEndpoint.USWest2))
            {
                var stream2 = new System.IO.MemoryStream();
                bitmap.Save(stream2, ImageFormat.Jpeg);

                stream2.Position = 0;
                PutObjectRequest request2 = new PutObjectRequest();
                request2.InputStream = stream2;
                request2.BucketName = "ezcimassets";
                request2.CannedACL = S3CannedACL.PublicRead;
                fileName = webpage + ".jpeg";
                //fileName = Guid.NewGuid() + webpage + ".jpeg";)
                request2.Key = "WebThumbnails/" + fileName;

                Amazon.S3.Model.PutObjectResponse response = s3Client.PutObject(request2);

            }

提前致谢

Answer 1

该行必须更改为

request2.CannedACL = S3CannedACL.PublicReadWrite

Answer 2

您可以检查具有该键的对象是否已经存在，如果存在，则将其删除：

public bool Exists(string fileKey, string bucketName)
{
        try
        {
            response = _s3Client.GetObjectMetadata(new GetObjectMetadataRequest()
               .WithBucketName(bucketName)
               .WithKey(key));

            return true;
        }

        catch (Amazon.S3.AmazonS3Exception ex)
        {
            if (ex.StatusCode == System.Net.HttpStatusCode.NotFound)
                return false;

            //status wasn't not found, so throw the exception
            throw;
        }
}

public void Delete(string fileKey, string bucketName)
{
    DeleteObjectRequest request = new DeleteObjectRequest();
    request.BucketName = bucketName;
    request.Key        = fileKey;
    client.DeleteObject(request);
}