Suggested way to add support for file extensions in the request URI in Spring 3.2

[cgendreau]

I'm a little bit confused about how I should implement this in Spring Web MVC 3.2.

What I want to do :

• page.json -> json response
• page.xml->xml response
• page.html -> FreeMarker template to generate html
• I want to ignore the "Accept" header since the extension is used

My controller

@Controller
public class APIController {
	//specific mapping for html to avoid @ResponseBody
	@RequestMapping(value="/page.html", method=RequestMethod.GET)
	public String handlePageHtmlGet(@RequestParam String data, ModelMap model, HttpServletResponse response){
		//...
		return "page"; //name of the view
	}

	@RequestMapping(value="/page", method=RequestMethod.GET)
	@ResponseBody
	public PageResponse handlePageGet(@RequestParam String data, HttpServletResponse response){
	//...
		return pageResponse;
	}
}

Note : PageResponse is just a regular POJO with Xml annotation.

My dispatcher-servlet.xml

<mvc:annotation-driven/>
<!-- Freemarker config -->
<bean id="freemarkerConfig" class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
  	<property name="templateLoaderPath" value="/WEB-INF/view/"/>
</bean>
	
<bean id="freeMarkerViewResolver" 
	class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
	<property name="cache" value="true"/>
	<property name="prefix" value=""/>
	<property name="suffix" value=".ftl"/>
	<property name="contentType" value="text/html;charset=UTF-8"/>
</bean>

This is working but here are my questions:

• How to restrict the supported extensions (If I try page.atom (or anything else that is not supported) an XML representation is returned)
• What is the purpose of ContentNegotiationManager in Spring 3.2?

[Marten Deinum]

You are confusing 2 things here, request mapping and result mapping.

If you only want to accept those extensions then explicitly map them (/page will by default also map /page.*).

Result mapping is done on different levels, where the file extension has precedence (by default). The result mapping is done/configured by the ContentNegotiationManager (I suggest a read of the reference guide and the javadocs of that class).

[cgendreau]

So I should do my mapping like that:

@RequestMapping(value="/page{extension:\\.(?:json|xml)}", method=RequestMethod.GET)

I read the ContentNegotiationManager reference guide and the javadocs and I'm ok with the default strategy/configuration.

I'm confused because a class like ContentNegotiatingViewResolver(result mapping) has a list of mediaTypes and a method setUseNotAcceptableStatusCode. So I thought that the extension restriction could be done at that level.