Part list/array gets resolved to all parts in current request [SPR-13893]

[spring-projects-issues]

Juergen Hoeller opened SPR-13893 and commented

Our support for Servlet 3.0 Part lists and arrays is unfortunately highly inconsistent with the MultipartFile handling that it was supposed to align with. Our MultipartRequest interface allows for access to multiple files which got uploaded under the same name; this is also what a declared MultipartFile list/array argument would receive. However, the Servlet 3.0 HttpServletRequest.getParts method does not retrieve parts by name but rather always returns all parts of the given request, so we accidentally called that method without any use of our specified part name... Let's make this consistent for 4.3.

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Affects: 4.2.4

Issue Links:

• Spring's support for javax.servlet.http.Part vs. MultipartFile incomplete, inconsistent [SPR-10591] #15220 Spring's support for javax.servlet.http.Part vs. MultipartFile incomplete, inconsistent
• RequestPartMethodArgumentResolver should defensively handle MethodParameter nesting level and java.util.Optional access [SPR-13850] #18423 RequestPartMethodArgumentResolver should defensively handle MethodParameter nesting level and java.util.Optional access
• @RequestPart(...) MultipartFile[] does not work (List<MultipartFile works) [SPR-11353] #15978 @RequestPart(...) MultipartFile[] does not work (List<MultipartFile works)
• MultipartFile argument requires multipart request even when optional (and empty) [SPR-13849] #18422 MultipartFile argument requires multipart request even when optional (and empty)
• Allow binding all MultipartFile instances as handler method argument [SPR-17405] #21938 Allow binding all MultipartFile instances as handler method argument

Referenced from: commits b4f33ad

[spring-projects-issues]

Juergen Hoeller commented

As of 4.3, Part list and array resolution takes the specified name into account, either from the annotation value or from the method parameter name.

If some application code accidentally relied on Part list/array resolution despite a name mismatch, it needs to be fixed to match the actual part name.

Juergen