如何为 AWS S3 分段上传生成 md5 校验和？答案

【问题标题】：How to generate md5 checksum for AWS S3 multi-part upload?如何为 AWS S3 分段上传生成 md5 校验和？
【发布时间】：2016-07-29 13:32:22
【问题描述】：

我已成功将多部分文件上传到 AWS S3，但现在我正尝试将 MD5 校验和添加到每个部分：

static void sendPart(existingBucketName, keyName, multipartRepsonse, partNum,
                     sendBuffer, partSize, vertx, partETags, s3, req, resultClosure)
{

    // Create request to upload a part.
    MessageDigest md = MessageDigest.getInstance("MD5")
    byte[] digest = md.digest(sendBuffer.bytes)
    println(digest.toString())
    InputStream inputStream = new ByteArrayInputStream(sendBuffer.bytes)
    UploadPartRequest uploadRequest = new UploadPartRequest()
        .withBucketName(existingBucketName).withKey(keyName)
        .withUploadId(multipartRepsonse.getUploadId()).withPartNumber(partNum)
        .withInputStream(inputStream)
        .withMD5Digest(Base64.getEncoder().encode(digest).toString())
        .withPartSize(partSize);

    // Upload part and add response to our list.
    vertx.executeBlocking({ future ->

            // Do the blocking operation in here

            // Imagine this was a call to a blocking API to get the result
            try {
                println("Sending chunk for ${keyName}")
                PartETag eTag = s3.uploadPart(uploadRequest).getPartETag()
                partETags.add(eTag);
                println("Etag: " + eTag.ETag)
                req.response().write("Sending Chunk\n")
            } catch(Exception e) {
            }

            def result = "success!"

            future.complete(result)
        }, resultClosure)
}

但是我收到以下错误：

AmazonS3Exception：您提供的 XML 格式不正确或没有针对我们发布的架构进行验证（服务：Amazon S3；状态代码：400；错误代码：MalformedXML；请求 ID：91542E819781FDFC)，S3 扩展请求 ID： yQs45H/ozn5+xlxV9lRgCQWwv6gQysT6A4ablq7/Epq06pUzy0qGvMc+YAkJjo/RsHk2dedH+pI=

我做错了什么？

【问题讨论】：

标签： amazon-web-services amazon-s3 multipart md5sum

【解决方案1】：

看来我的摘要转换不正确。

static void sendPart(existingBucketName, keyName, multipartRepsonse, partNum,
                     sendBuffer, partSize, vertx, partETags, s3, req, resultClosure)
{

    // Create request to upload a part.
    MessageDigest md = MessageDigest.getInstance("MD5")
    byte[] digest = md.digest(sendBuffer.bytes)
    InputStream inputStream = new ByteArrayInputStream(sendBuffer.bytes)
    UploadPartRequest uploadRequest = new UploadPartRequest()
        .withBucketName(existingBucketName).withKey(keyName)
        .withUploadId(multipartRepsonse.getUploadId()).withPartNumber(partNum)
        .withInputStream(inputStream)
        .withMD5Digest(Base64.getEncoder().encodeToString(digest))
        .withPartSize(partSize)

    // Upload part and add response to our list.
    vertx.executeBlocking({ future ->

            try {
                println("Sending chunk for ${keyName}")
                PartETag eTag = s3.uploadPart(uploadRequest).getPartETag()
                partETags.add(eTag);
                req.response().write("Sending Chunk\n")
            } catch(Exception e) {
            }

            def result = "success!"

            future.complete(result)
        }, resultClosure)
}

【讨论】：