如何将多部分文件作为inputstream直接流式传输到Java中的AWS S3？

现在，我的代码获取MultipartFile并将其转换为java.util.File并上传到S3

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());
}

我不想这样做的原因是，在我的桌面上，我在浏览器中上传的图像暂时停留在tomcat服务器中，然后上传到S3

但当我的webapp在Ec2中运行时，由于权限问题（或其他原因），从浏览器上传的图像似乎不会留在tomcat服务器中。因此，整个图像上传失败

我尝试了本文提供的解决方案，但运气不好

---

有人能用代码指导我将一个多部分文件直接流式传输到S3吗？

在jsp的表单标记中，确保编写enctype=“multipart/form data”。然后在servlet中声明下面的代码

@WebServlet（name=“ServletName”，urlPatterns={”/ServletName}）

您可以在servlet中编写以下代码，以inputStream的形式获取文件并将其上载到S3中

    Part filePart=  request.getPart("FileName"); // The name of <input type=file name="FileName"> in jsp form. Here, FileName 

 try {

                    InputStream inputStream=null;

                    if(filePart!=null){

                    inputStream=filePart.getInputStream();   //get file in form of inputstream


                                      }

          ObjectMetadata md = new ObjectMetadata();
          md.setContentLength(filePart.getSize());
          md.setContentType(filePart.getContentType());

        try {
        final AmazonS3 s3Client = AmazonS3ClientBuilder.standard().build();
        versionId = s3Client.putObject(new PutObjectRequest("bucketName", name, inputStream,md))
                .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());
}

partfilepart=request.getPart（“文件名”）；//以jsp形式显示的名称。这里，文件名
试一试{
InputStream InputStream=null；
if（filePart！=null）{
inputStream=filePart.getInputStream（）；//以inputStream的形式获取文件
}
ObjectMetadata md=新的ObjectMetadata（）；
md.setContentLength（filePart.getSize（））；
md.setContentType（filePart.getContentType（））；
试一试{
最终AmazonS3 s3Client=AmazonS3ClientBuilder.standard（）.build（）；
versionId=s3Client.putObject（新的PutObjectRequest（“bucketName”，name，inputStream，md））
.getVersionId（）；
}捕获（最终AmazonServiceException ase）{
System.out.println（“捕获到一个AmazonServiceException，它”
+“意味着是你提出的请求”
+“发送到AmazonS3，但由于某种原因被拒绝，错误响应为“+”）；
System.out.println（“错误消息：+ase.getMessage（））；
System.out.println（“HTTP状态代码：+ase.getStatusCode（））；
System.out.println（“AWS错误代码：+ase.getErrorCode（））；
System.out.println（“错误类型：+ase.getErrorType（））；
System.out.println（“请求ID:+ase.getRequestId（））；
}捕获（最终AmazonClientException ace）{
System.out.println（“捕获了AmazonClientException，这意味着”
+客户端在尝试执行时遇到“+”内部错误
+“与S3通信，”+“例如无法访问网络。”）；
System.out.println（“错误消息：+ace.getMessage（））；
}
}捕获（最终异常e）{
log.error（“您未能上载”+name+“=>”+e.getMessage（））；
}

我认为没有一个PutObjectRequest构造函数有三个参数

    Part filePart=  request.getPart("FileName"); // The name of <input type=file name="FileName"> in jsp form. Here, FileName 

 try {

                    InputStream inputStream=null;

                    if(filePart!=null){

                    inputStream=filePart.getInputStream();   //get file in form of inputstream


                                      }

          ObjectMetadata md = new ObjectMetadata();
          md.setContentLength(filePart.getSize());
          md.setContentType(filePart.getContentType());

        try {
        final AmazonS3 s3Client = AmazonS3ClientBuilder.standard().build();
        versionId = s3Client.putObject(new PutObjectRequest("bucketName", name, inputStream,md))
                .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());
}