WebClient: Multipart POST doesn't work [SPR-15948]

[spring-projects-issues]

Abhijit Sarkar opened SPR-15948 and commented

Using 5.0.0.BUILD-SNAPSHOT, not RC3.

I understand that #19114 added multipart support for WebClient, and I also looked at the integration tests, but sadly, it doesn't work for the following request made using WebClient.

curl -v --trace-ascii /dev/stdout -F board=sarkara1/test -F note=test -F image=@test.png "https://api.pinterest.com/v1/pins/?access_token=xxx"

I keep getting the error "400 board is required" from the server. I'm not saying Pinterest API is the best designed in the world, actually it's quite the contrary, but the above curl statement works, and so does an OkHttp client, so I've to believe that it's a bug with WebClient.

By dumping the request body, and comparing it with those from the working versions, I've noticed that WebClient adds a Content-Type: text/plain header for simple form fields like board and note above, while the other clients don't. If I remember correctly, WebClient also adds a ;utf-8 after the overall Content-Type boundary, which the other clients don't. There may be other differences that I'm failing to report now, since it was done in a caffeine-fuelled, late-night, debugging session. Also see #20500 which is adding to the differences.

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Affects: 5.0 RC3

Issue Links:

• WebClient: DELETE request should not send transfer-encoding: chunked header [SPR-15947] #20500 WebClient: DELETE request should not send transfer-encoding: chunked header
• Reactive multipart request support [SPR-14546] #19114 Reactive multipart request support

0 votes, 5 watchers

[spring-projects-issues]

Brian Clozel commented

Please update your question with the WebClient code you're using, or better, a repro project.

Even if it is useful, we can't work from your own interpretation of the issue, but rather the issue itself: what were you trying to do? what did you try to achieve that? what did happen? what did you expect to happen instead?

[spring-projects-issues]

Abhijit Sarkar commented

Looks like I somehow missed the notification, or it was never sent out, of a follow up comment. The code that's not working is here https://github.com/asarkar/spring/blob/master/pinterest-client/src/main/kotlin/org/abhijitsarkar/spring/pinterest/client/Pinterest.kt#L257. I had to use OkHttp instead because of this bug.

[spring-projects-issues]

Sébastien Deleuze commented

Could you please update to Spring Framework 5.0.3 and say us if the issue is still present?

[spring-projects-issues]

Abhijit Sarkar commented

This was several months ago, and I'll have to try to reproduce this error. If and when I am able to, I'll post an update.

[spring-projects-issues]

Rossen Stoyanchev commented

We had this #20793 resolved recently which might have been the reason.

[spring-projects-issues]

Sébastien Deleuze commented

Abhijit Sarkar Any chance you could test with Spring Framework 5.0.4 and send us your feedback?

[spring-projects-issues]

Abhijit Sarkar commented

After 6 months, I no longer remember the context, and also don't have the original code. Feel free to close the issue.