i configure my messageconverter as Jackson's then

class Foo{int x; int y}

and in controller

@ResponseBody
public Foo method(){
   return new Foo(3,4)
}

from that i m expecting to return a JSON string {x:'3',y:'4'} from server without any other configuration. but getting 404 error response to my ajax request

If the method is annotated with @ResponseBody, the return type is written to the response HTTP body. The return value will be converted to the declared method argument type using HttpMessageConverters.

Am I wrong ? or should I convert my response Object to Json string myself using serializer and then returning that string as response.(I could make string responses correctly) or should I make some other configurations ? like adding annotations for class Foo

here is my conf.xml

<bean id="jacksonMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter">

  <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="messageConverters">
  <list>
    <ref bean="jacksonMessageConverter"/>
  </list>
</property>