AnnotationMethodHandlerAdapter should treat String return type with @ModelAttribute as model attribute instead of view name [SPR-4867]

[spring-projects-issues]

Joris Kuipers opened SPR-4867 and commented

Currently, AnnotationMethodHandlerAdapter.getModelAndView treats all String return types as view names. It might make sense to support returning a String as a model attribute by annotating the method with @ModelAttribute. Even though this would be an incompatible change, the combination of @ModelAttribute with a String return type is meaningless at the moment so this shouldn't cause any problems. Otherwise, I think that we should at least issue a warning if someone uses this combination.

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Affects: 2.5.4

Referenced from: commits 72cc060

[spring-projects-issues]

Joris Kuipers commented

Oh, BTW: this goes for a Map being returned as well. Just check for the presence of @ModelAttribute first, before going over the other supported return types.

[spring-projects-issues]

Juergen Hoeller commented

Good point! Makes sense for request handler methods with an @ModelAttribute annotation to always return a model attribute.

Juergen

[spring-projects-issues]

Neale Upstone commented

Any chance of documenting this in the @ModelAttribute javadoc. I don't really think I should have needed to go to the Source tab to see your deltas to understand how this works... but... at least the code is self explanatory :)