amazon-s3 - 异常 "The Content-MD5 you specified did not match what we received"

Question

在测试将文件从 ec2 上传到 s3 的应用程序时，我遇到了一个异常(exception)，这是我以前从未遇到过的。内容为:

Exception in thread "Thread-1" com.amazonaws.services.s3.model.AmazonS3Exception: The Content-MD5 you specified did not match what we received. (Service: Amazon S3; Status Code: 400; Error Code: BadDigest; Request ID: 972CB8E04388AB20), S3 Extended Request ID: T7bmFnQ2RlGWlJD+aGYfTy97XZw88pbQrwNB8YCezSjyq6O2joxHRP/6ko+Q2zZeGewkw4x/90k=
    at com.amazonaws.http.AmazonHttpClient.handleErrorResponse(AmazonHttpClient.java:1383)
    at com.amazonaws.http.AmazonHttpClient.executeOneRequest(AmazonHttpClient.java:902)
    at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:607)
    at com.amazonaws.http.AmazonHttpClient.doExecute(AmazonHttpClient.java:376)
    at com.amazonaws.http.AmazonHttpClient.executeWithTimer(AmazonHttpClient.java:338)
    at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:287)
    at com.amazonaws.services.s3.AmazonS3Client.invoke(AmazonS3Client.java:3676)
    at com.amazonaws.services.s3.AmazonS3Client.putObject(AmazonS3Client.java:1439)
    at com.amazonaws.services.s3.transfer.internal.UploadCallable.uploadInOneChunk(UploadCallable.java:131)
    at com.amazonaws.services.s3.transfer.internal.UploadCallable.call(UploadCallable.java:123)
    at com.amazonaws.services.s3.transfer.internal.UploadMonitor.call(UploadMonitor.java:139)
    at com.amazonaws.services.s3.transfer.internal.UploadMonitor.call(UploadMonitor.java:47)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

我可以做什么来修复这个错误？我在应用程序中使用了与之前相同的代码。

Answer 1

我想我已经解决了我的问题。我终于发现我的一些文件在上传过程中实际上发生了变化。由于文件是由另一个线程生成的，因此上传和生成是同时完成的。文件不能立即生成，在生成文件的过程中，可能同时上传，文件在上传过程中实际上发生了变化。

文件的md5是在开始上传时由AmazonS3Client创建的，然后将整个文件上传到S3，此时文件与开始上传的文件不同，因此md5实际上发生了变化。我将程序修改为单线程程序，问题再也没有出现。