Add HttpHeaders getter and setter for Content-Language [SPR-14536]

[spring-projects-issues]

Daniel Fernández opened SPR-14536 and commented

Now that content negotiation is in place at the View/ViewResolver mechanism and therefore View implementations don't need to manually create the Content-Type HTTP header, it would be nice to have a similar mechanism that avoided the manual creation of the Content-Language header.

The current code at the reactive version of ThymeleafView (see here) does something like:

final HttpHeaders responseHeaders = exchange.getResponse().getHeaders();
if (templateLocale != null) {
    responseHeaders.set("Content-Language", templateLocale.toString());
}

However, in Spring MVC thanks to the HttpServletResponse#setLocale(Locale) method, all it had to do is:

response.setLocale(templateLocale);

It's not that creating this header is extremely ugly code, but anyway IMHO it would be great if Spring Reactive included some kind of higher-level mechanism for setting this Content-Language that kept View implementations from having to create it manually.

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Affects: 5.0 M1

Issue Links:

• Content-Language not set for responses rendered with Message Converters [SPR-14802] #19368 Content-Language not set for responses rendered with Message Converters
• Add HttpHeaders getter and setter for Accept-Language [SPR-15024] #19591 Add HttpHeaders getter and setter for Accept-Language
• Overloaded convenience setters on HttpHeaders [SPR-16562] #21104 Overloaded convenience setters on HttpHeaders

Referenced from: commits 36da299

[spring-projects-issues]

Sébastien Deleuze commented

Rossen Stoyanchev I think I can take care of this one if you don't mind.

[spring-projects-issues]

Rossen Stoyanchev commented

It might make sense to start with support in HttpHeaders for Accept-Language and Content-Language accepting and returning Locale or List<Locale> in the case of Accept-Language.

That might even be all that needs to be done for this ticket since setContentLanguage can check the input locale for null.

[spring-projects-issues]

Sébastien Deleuze commented

Fixed by this commit. See also #19591 that adds Accept-Language getter and setter.