Java 堆空间不足，无法在 AWS S3 上上传文件

Question

我正在尝试使用 Java-AWS API 在 AWS S3 上上传文件。问题是我的应用程序无法上传大文件，因为堆已达到其限制。错误:java.lang.OutOfMemoryError:Java 堆空间

我个人认为扩展堆内存不是永久的解决方案，因为我必须上传高达 100 GB 的文件。我该怎么办？

这是代码片段:

        BasicAWSCredentials awsCreds = new BasicAWSCredentials(AID, Akey);
        AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
        .withRegion(Regions.fromName("us-east-2"))
        .withCredentials(new AWSStaticCredentialsProvider(awsCreds))
        .build();

        InputStream Is=file.getInputStream();

        boolean buckflag = s3Client.doesBucketExist(ABuck);
        if(buckflag != true){
           s3Client.createBucket(ABuck);
        }
        s3Client.putObject(new PutObjectRequest(ABuck, AFkey,file.getInputStream(),new ObjectMetadata() ).withCannedAcl(CannedAccessControlList.PublicRead));

Answer 1

我强烈建议在 ObjectMetadata 上使用 setContentLength()，因为:

..If not provided, the library will have to buffer the contents of the input stream in order to calculate it.

(..这可以预见会导致“足够大”的文件出现 OutOfMemory。)

来源:PutObjectRequest javadoc

应用于您的代码:

 // ...
 ObjectMetadata omd = new ObjectMetadata();
 // a tiny code line, but with a "huge" information gain and memory saving!;)
 omd.setContentLength(file.length());

 s3Client.putObject(new PutObjectRequest(ABuck, AFkey, file.getInputStream(), omd).withCannedAcl(CannedAccessControlList.PublicRead));
 // ...