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

问题

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.

回答1:

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

@Configuration
@EnableWebMvc
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.

回答2:

If you use spring 3.2.x, just add this to spring-mvc.xml

<mvc:annotation-driven content-negotiation-manager="contentNegotiationManager" />
<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
    <property name="favorPathExtension" value="false"/>
    <property name="mediaTypes">
        <value>
            json=application/json
            xml=application/xml
        </value>
    </property>
    <property name="defaultContentType" value="application/json"/>
</bean>

来源：https://stackoverflow.com/questions/18189245/how-to-set-the-default-content-type-in-spring-mvc-in-no-accept-header-is-provide

标签

http

rest

spring-mvc

content-negotiation