如何将图像直接上传到S3，而不让Ec2中运行的java webapp存储多部分图像？

在我的笔记本电脑localhost中

下面的代码通过浏览器上传图片，然后上传到S3

我知道弹性Beanstalk应用程序运行在没有持久本地存储的AmazonEC2实例上。我们应该直接将文件写入S3

当我的java webapp在Ec2实例中运行时，如何将文件直接写入S3？

这是我用来将图像上传到S3的代码，它在我的本地主机上运行良好

try {
            final ObjectMetadata objectMetadata = new ObjectMetadata();
            objectMetadata.setContentType(file.getContentType());
            byte[] contentBytes = null;
            try {
              final InputStream is = file.getInputStream();
              contentBytes = IOUtils.toByteArray(is);
            } catch (final IOException e) {
              log.error("Failed while reading bytes from %s" + e.getMessage());
            }

            final Long contentLength = Long.valueOf(contentBytes.length);
            objectMetadata.setContentLength(contentLength);
            objectMetadata.setHeader("filename", fileNameWithExtn);

            /*
             * Reobtain the tmp uploaded file as input stream
             */
            final InputStream inputStream = file.getInputStream();

            final File convFile = new File(fileNameWithExtn);
            file.transferTo(convFile);


            FileUtils.copyInputStreamToFile(inputStream, convFile);
            try {

              final AmazonS3 s3Client = AmazonS3ClientBuilder.standard().build();
              versionId = s3Client.putObject(new PutObjectRequest("bucketName", name, convFile))
                  .getVersionId();
            } catch (final AmazonServiceException ase) {
              System.out.println("Caught an AmazonServiceException, which"
                  + " means your request made it "
                  + "to Amazon S3, but was rejected with an error response" + " for some reason.");
              System.out.println("Error Message:    " + ase.getMessage());
              System.out.println("HTTP Status Code: " + ase.getStatusCode());
              System.out.println("AWS Error Code:   " + ase.getErrorCode());
              System.out.println("Error Type:       " + ase.getErrorType());
              System.out.println("Request ID:       " + ase.getRequestId());
            } catch (final AmazonClientException ace) {
              System.out.println("Caught an AmazonClientException, which means"
                  + " the client encountered " + "an internal error while trying to "
                  + "communicate with S3, " + "such as not being able to access the network.");
              System.out.println("Error Message: " + ace.getMessage());
            }
          } catch (final Exception e) {
            log.error("You failed to upload " + name + " => " + e.getMessage());
          }

我检查了这篇文章，但其中一个答案说它不适用于文件或字符串，而其他答案没有明确的代码或答案

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请帮忙

您可以尝试直接使用前端，查看S3文档中关于直接向S3提交html表单的内容 检查链接以供参考 将表单数据直接上传到AWS S3-Stuff…和Things…（） 使用HTML5和Backbone.js（）将图像文件直接从web浏览器保存到S3，您也可以通过java来实现。下面的代码将文件直接存储到s3，而不将其本地存储在EC2上

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仅仅因为本地存储在重启之间不是持久的，并不意味着它不存在。您可以将文件临时存储在本地文件系统上，只要您不依赖这些文件在以后的任何特定时间可用。另请参见：（如何附加短命卷）谢谢。但是，如果我想检查图像文件并对其进行处理，然后将其存储到后端，该怎么办呢。我想检查，做些别的事情，然后保存到S3。你可以进行内存访问并应用更改

public boolean uploadFileDirectlyToS3(MultipartFile multipartFile, String keyName) {
        ObjectMetadata data = new ObjectMetadata();
        try {
            data.setContentType(multipartFile.getContentType());
            data.setContentLength(multipartFile.getSize());
            s3Client.putObject(CORE_BUNDLE.getString("bucket.name"), keyName, multipartFile.getInputStream(), data); 
//KeyName is the specific and unique path where you wanna place your file in s3
            return true;
        } catch (Exception e) {
            logger.error("Error occured while uploading file to s3 having name: "+multipartFile.getOriginalFilename(), e);
            return false;
        }
    }