Support use of MultipartFile as input to RestTemplate or WebClient [SPR-16808]

[spring-projects-issues]

Andrew Neeson opened SPR-16808 and commented

I had a need to proxy a MultipartFile from a controller to a RestTemplate.  I did not want the contents of this file to be stored locally (as with FileSystemResource or ByteArrayResource) so I created a MultipartFileResource.

I though this would be a useful addition to Spring's resource types, so I intended to submit a pull request.  Upon searching for similar issues I found #18147.

After reading through the comments, my understanding was that the resource wasn't created because of issues opening the InputStream twice.  Once for the getInputStream() call and another by the contentLength() call (by virtue of AbstractResource using the inputstream to calculate this value).

However a MultipartFile already provides the content length (without accessing the InputStream).  So why not use that?  I.e.

@Override
public long contentLength() throws IOException {
 return multipartFile.getSize();
}

 

Assuming that:

• That was that only problem with resttemplate multipart post with InputStreamResource not working [SPR-13571] #18147
• The above suggestion solves it

 I would like Spring to include a MultipartFileResource.  I'd be happy to submit a PR.

 

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Affects: 5.0.6

Issue Links:

• resttemplate multipart post with InputStreamResource not working [SPR-13571] #18147 resttemplate multipart post with InputStreamResource not working

[spring-projects-issues]

Rossen Stoyanchev commented

Juergen Hoeller, what about exposing a getResource method on MultipartFile? That saves the need for a public, custom implementation of Resource and exposes the option where it's easy to discover. It lines well next to getInputStream.

It could be done as a default method that builds on getInputStream and getOriginalFileName and creates a package-private implementation of Resource.

[spring-projects-issues]

Andrew Neeson commented

rstoyanchev+1