$.postJSON(
    "controller.do"
   , {   action: "list", 
          key: "key",
          params: [ "param1", "param2", "param3" ]
     }
    , function( data ) {
    }
};

{   action: "list", 
     key: "key",
     params: [ "param1", "param2", "param3" ]
 }

@RequestMapping(value="/controller.do", method=RequestMethod.POST) 
public void addDocFileJson(
	HttpServletRequest request
	, HttpServletResponse response ){

	ObjectMapper mapper = new ObjectMapper();

              // Входящий Поток JSON превратить в объект input
             Input input = mapper.readValue( request.getInputStream() , Class Input... ); 
             .......
             Result result = new Result();
              ......
             // Исходящий result передать  
             response.setContentType( MediaType.APPLICATION_JSON+"; charset=utf-8" );			
             mapper.writeValue(response.getOutputStream(),  result);

@RequestMapping(value="/controller.do")
public @ResponseBody Result autocomplete_jdbc(@RequestBody Input query) {

       Result result = new Result();
       ......
       return result;
}

	<mvc:annotation-driven>
	    <mvc:message-converters>
		<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
		</bean>
	    </mvc:message-converters>
	</mvc:annotation-driven>

	<mvc:annotation-driven>
	    <mvc:message-converters>
		<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
		    <property name="objectMapper">
			<bean class="ru.stb.sharov.web.json.HibernateAwareObjectMapper" />
		    </property>
		</bean>
	    </mvc:message-converters>
	</mvc:annotation-driven>