HTTP request with invalid "Accept" header causes HTTP 500

[maio]

Steps to reproduce:

1. Create new app at https://start.spring.io/ with Spring Web dependency - config
2. Start the app ./gradlew bootRun
3. Send HTTP request curl -I -H "Accept: yaml" http://localhost:8080/some-path

Expected response: HTTP 400 bad request (or similar)
Actual response: HTTP 500 - internal server error

2023-08-02T16:10:16.524+02:00 ERROR 6385 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed: org.springframework.http.InvalidMediaTypeException: Invalid mime type "yaml": does not contain '/'] with root cause

org.springframework.util.InvalidMimeTypeException: Invalid mime type "yaml": does not contain '/'
        at org.springframework.util.MimeTypeUtils.parseMimeTypeInternal(MimeTypeUtils.java:229) ~[spring-core-6.1.0-M3.jar:6.1.0-M3]
        at org.springframework.util.ConcurrentLruCache.get(ConcurrentLruCache.java:100) ~[spring-core-6.1.0-M3.jar:6.1.0-M3]
        at org.springframework.util.MimeTypeUtils.parseMimeType(MimeTypeUtils.java:213) ~[spring-core-6.1.0-M3.jar:6.1.0-M3]
        at org.springframework.http.MediaType.parseMediaType(MediaType.java:739) ~[spring-web-6.1.0-M3.jar:6.1.0-M3]
        at org.springframework.http.MediaType.parseMediaTypes(MediaType.java:768) ~[spring-web-6.1.0-M3.jar:6.1.0-M3]
        at org.springframework.boot.autoconfigure.web.servlet.WelcomePageHandlerMapping.getAcceptedMediaTypes(WelcomePageHandlerMapping.java:82) ~[spring-boot-autoconfigure-3.2.0-SNAPSHOT.jar:3.2.0-SNAPSHOT]
        at org.springframework.boot.autoconfigure.web.servlet.WelcomePageHandlerMapping.isHtmlTextAccepted(WelcomePageHandlerMapping.java:71) ~[spring-boot-autoconfigure-3.2.0-SNAPSHOT.jar:3.2.0-SNAPSHOT]
        at org.springframework.boot.autoconfigure.web.servlet.WelcomePageHandlerMapping.getHandlerInternal(WelcomePageHandlerMapping.java:67) ~[spring-boot-autoconfigure-3.2.0-SNAPSHOT.jar:3.2.0-SNAPSHOT]

[ASDasd341]

can i look into it?

[rstoyanchev]

The MediaType parsing code raises InvalidMediaTypeException and it's up to the calling code decide how to handle that. In this case it's Boot's WelcomePageHandlerMapping that needs to decide what should be done, whether to ignore it, or handle it, or raise another exception that would be handled as a 400 error.

We handle InvalidMediaTypeException in various places in Spring MVC and WebFlux. Sometimes we ignore it, and sometimes we raise HttpMediaTypeNotSupportedException which becomes a 400.

So I think this issue belongs in Boot's issue tracker. Not much we can do from our end.

[bclozel]

duplicates spring-projects/spring-boot/issues/37118