How to set the default content type in Spring MVC in no Accept header is provided?

Question

If a request is sent to my API without an Accept header, I want to make JSON the default format. I have two methods in my controller, one for XML and one for JSON:

@RequestMapping(method = RequestMethod.GET,produces=MediaType.APPLICATION_ATOM_XML_VALUE)
@ResponseBody
public ResponseEntity<SearchResultResource> getXmlData(final HttpServletRequest request) {
     //get data, set XML content type in header.
 }

 @RequestMapping(method = RequestMethod.GET, produces=MediaType.APPLICATION_JSON_VALUE)
 @ResponseBody
 public ResponseEntity<Feed> getJsonData(final HttpServletRequest request){
      //get data, set JSON content type in header.  
 }

When I send a request without an Accept header the getXmlData method is called, which is not what I want. Is there a way to tell Spring MVC to call the getJsonData method if no Accept header has been provided?

EDIT:

There is a defaultContentType field in the ContentNegotiationManagerFactoryBean that does the trick.

Answer 1

From the Spring documentation, you can do this with Java config like this:

@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
  @Override
  public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
    configurer.defaultContentType(MediaType.APPLICATION_JSON);
  }
}

---

If you are using Spring 5.0 or later, implement WebMvcConfigurer instead of extending WebMvcConfigurerAdapter. WebMvcConfigurerAdapter has been deprecated since WebMvcConfigurer has default methods (made possible by Java 8) and can be implemented directly without the need for an adapter.