生成S3 URL以在Android中获取图像

Question

在我们的项目中，我们配置了Amazon webservice。在Android应用程序端，它需要生成s3 url以从服务器获取图像。通过使用下面的代码，我试图获取图像，但每次遇到Signature失败或任何其他异常。

//Set the google token in map 
      Map<String, String> logins = new HashMap<>(); 
      logins.put(AppConstants.GOOGLE_CONSTANT, token); 

      //Initialize amazon cognito credentials provider 
      CognitoCachingCredentialsProvider credentialsProvider = new CognitoCachingCredentialsProvider(
        activity, // Context 
        AppConstants.IDENTITY_POOL_ID, // Identity Pool ID 
        Regions.US_EAST_1 // Region 
      ); 

      //Set the google credentials 
      credentialsProvider.setLogins(logins); 

AmazonS3 s3client = new AmazonS3Client(credentialsProvider); 

java.util.Date expiration = new java.util.Date(); 
long msec = expiration.getTime(); 
msec += 1000 * 60 * 60; // 1 hour. 
expiration.setTime(msec); 

GeneratePresignedUrlRequest generatePresignedUrlRequest = 
      new GeneratePresignedUrlRequest(bucketName, objectKey); 
generatePresignedUrlRequest.setMethod(HttpMethod.GET); // Default. 
generatePresignedUrlRequest.setExpiration(expiration); 

URL s = s3client.generatePresignedUrl(generatePresignedUrlRequest); 

这里，当我尝试在浏览器中加载接收URL时，它会抛出一个Signature错误。

问题是，所有的帮助都是针对Java的。我没有找到任何Android的具体帮助。

我刚才提到以下站点 https://aws.amazon.com/blogs/developer/generating-amazon-s3-pre-signed-urls-with-sse-kms-part-2/ http://docs.aws.amazon.com/AmazonS3/latest/dev/ShareObjectPreSignedURLJavaSDK.html

Answer 1

您可以使用下面的代码用于获取预签取得网址。

URL presignedUrl = s3.generatePresignedUrl(
      bucketName, key, new Date(new Date().getTime() + 1000 * 60 * 60)); 
System.out.println(presignedUrl.toExternalForm()); 

HttpURLConnection connection = connectToPresignedUrl(
      s3, new GeneratePresignedUrlRequest(bucketName, key)); 
assertEquals(200, connection.getResponseCode());