Empty or blank required UUID header validation results in 200 response status

[maxdewil]

Affects: Spring MVC 5.1.9.RELEASE

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Hi,

My REST API takes as input a mandatory X-Request-ID header that is transformed to a UUID object.

So my REST controller method has this parameter:
@RequestHeader(value="X-Request-ID", required=true) UUID xRequestID

However, if the X-Request-ID HTTP header:

• is absent : 400 Bad Request (OK)
• is empty (i.e. the empty string) : 200 OK (NOK, should be 400)
• is blank (i.e. a string with whitespace only) : 200 OK (NOK, should be 400)
• is not a UUID (for instance "foobar") : 400 Bad Request (OK)

It seems that the problem comes from:

1. 'is empty' case: StringToUUIDConverter returns null
2. 'is blank' case: StringToUUIDConverter fails, then Spring MVC defaults to UUIDEditor that returns null.

[sbrannen]

In 92228f0, I introduced tests for the status quo.

@maxdewil, is my assumption correct that you would expect argument resolution for an empty or blank UUID header to result in a MethodArgumentConversionNotSupportedException instead of null?

[sbrannen]

This issue also inspired #23940.

[maxdewil]

@maxdewil, is my assumption correct that you would expect argument resolution for an empty or blank UUID header to result in a MethodArgumentConversionNotSupportedException instead of null?

If I pass the header value "foobar", the following exception is thrown : org.springframework.web.method.annotation.MethodArgumentTypeMismatchException: Failed to convert value of type 'java.lang.String' to required type 'java.util.UUID'; nested exception is java.lang.IllegalArgumentException: Invalid UUID string: foobar

I think the behavior should be the same for an empty/blank string.

[sbrannen]

I think the behavior should be the same for an empty/blank string.

OK. We'll see if that's feasible.