Spring register a new JSON Converter

Yesterday I had to modify the JSON during creation from an object. I want to add validation hints along with the json that travelled to the server.  Spring has converters and uses MappingJacksonHttpMessageConverter to convert the object returned by the controller. SO i want to modify the converter to include the hints in the JSON generated.

A lot of googling happened for no luck finally I got the solution which reads as follows

First override the default handler: MappingJsonHttpMessageConverter

public class JSONHttpMessageConverter extends MappingJacksonHttpMessageConverter {
…

…
    @Override
    protected void writeInternal(Object object, HttpOutputMessage outputMessage) throws IOException,
                                                                                HttpMessageNotWritableException {

now in spring xml modify the mvc:annotation-config; Please make sure that u dont have another annotation-config with in any of the spring xmls in ur classpath.

    <mvc:annotation-driven  validator="ExtendedValidatationAdaptor" >
        <mvc:message-converters  register-defaults="true" >
            <bean class="wavecrest.foundation.validate.web.JSONHttpMessageConverter" p:somebean-ref="somref" />
        </mvc:message-converters>
    </mvc:annotation-driven>

and this should do. 

Tested with spring-web-3.1.1.RELEASE.jar