@Override
  protected void writeInternal(final Object object, final HttpOutputMessage outputMessage)
      throws IOException, HttpMessageNotWritableException {
    HttpOutputMessageWrapper outputMessageWrapper =
        new BufferingHttpOutputMessageWrapper(outputMessage);
    super.writeInternal(object, outputMessageWrapper);
    outputMessageWrapper.flush();
  }
The CustomMappingJackson2HttpMessageConverter class...

@see org.springframework.http.converter.json.MappingJackson2HttpMessageConverter
@since GemFire 0.0.1
geode-web-api/src/main/java/org/apache/geode/rest/internal/web/http/converter/CustomMappingJackson2HttpMessageConverter.java