Handle HTML and non-HTML representations in controller with HttpMessageConverters - spring

Question

I have a Spring MVC controller for a RESTful resource (ServiceDirectoryController), which I want to serve both HTML (web page) and non HTML (web service) representations. I want to use view names and JSP to generate the HTML representation, but HttpMessageConverters for the other representations. How do I do that?
I've implemented the request handling method for the non-HTML representations. My internal (domain-model) representation is ThingNames, for which I have suitable message converters, so the request handling method is simply:
#RequestMapping(value = { "/directory/" }, method = RequestMethod.GET)
#ResponseBody
public ThingNames retrieveThings() {
...
}
Now I want to add the request handling method for the JSP page. So I need a method that indicates the view name and provides a suitable model. So, the obvious thing to do is this:
#RequestMapping(value = { "/directory/" }, method = RequestMethod.GET)
public String retrieveThings(Map< String, Object > model) {
...
}
with the view name as the return value.
But will that work? Is Spring clever enough to work out that the HTML representation should be handled by the second method, and use the first method for all other representations? And if not, how do I go about handling both JSP/HTML and non JSP/HTML representations?

Answer 1

According to a Spring blog post by Paul Chapman, my controller will work as written if I set up a PPA Content Negotiation Strategy. That is, if I configure Spring to consider clues about the wanted content type in the following descending order of preference:
Path extension (.htm, .tsv, etc.)
Request parameter (?format=htm, ?format=xls)
Accept header (proper HTTP content negotiation, which sadly works poorly with HTML browsers).
What is more, the Spring provided ContentNegotiationManagerFactoryBean operates in just that order.
In addition, you must annotate the handler methods in the controller so Spring knows that those methods should handle HTML content, using the consumes and produces values of the #RequestMapping annotation. That is, instead of simply writing
#RequestMapping(value = { "/directory/" }, method = RequestMethod.GET)
#ResponseBody
public String retrieveThings(Map< String, Object > model) {
...
}
write
#RequestMapping(value = { "/directory/" }, method = RequestMethod.GET,
produces = MediaType.TEXT_HTML_VALUE)
#ResponseBody
public String retrieveThings(Map< String, Object > model) {
...
}