[FIXED] Java/Spring MVC: List mediaTypes / Read Content Negotiation Settings

Issue

I want to make an endpoint which tells the user, which mediaTypes are registered for contentNegotiation.

These are my settings

     configurer
            .favorPathExtension(false)
            .favorParameter(true)
            .parameterName("mediaType")
            .ignoreAcceptHeader(true)
            .useJaf(false)
            .defaultContentType(MediaType.APPLICATION_JSON_UTF8)
            .mediaType("json", MediaType.APPLICATION_JSON_UTF8)
            .mediaType("pdf", MediaType.APPLICATION_PDF)
            .mediaType("html", MediaType.TEXT_HTML)
            .mediaType("csv", new MediaType("text", "csv"));

How can I read them in controller? I am hoping for some function whateverService.getMediaTypes which gives back ["json", "pdf", "html", "csv"].

Edit:
Alternatively a method to get all AbstractHttpMessageConverter and their MediaTypes.

Solution

Try something like this:

@RestController
public class YourRest {

    ...

    @Autowired
    private ContentNegotiationManager contentNegotiationManager;

    @RequestMapping(value = "types", method = RequestMethod.GET)
    public Set<String> getConfiguredMediaTypes() {
        return Optional.of(contentNegotiationManager)
                .map(m -> m.getStrategy(ParameterContentNegotiationStrategy.class))
                .map(s -> s.getMediaTypes().keySet())
                .orElse(Collections.emptySet());
    }

    ...
}

Answered By - Nikolai Shevchenko
Answer Checked By - Marilyn (JavaFixing Volunteer)