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

public class JsonMimeInterceptor implements ClientHttpRequestInterceptor {

  @Override
  public ClientHttpResponse intercept(HttpRequest request, byte[] body,
        ClientHttpRequestExecution execution) throws IOException {
    HttpHeaders headers = request.getHeaders();
    headers.add("Accept", MediaType.APPLICATION_JSON);
    return execution.execute(request, body);
  }
}

@Configuration
public class MyAppConfig {

  @Bean
  public RestTemplate restTemplate() {
      RestTemplate restTemplate = new RestTemplate(clientHttpRequestFactory());
      restTemplate.setInterceptors(Collections.singletonList(new JsonMimeInterceptor()));
      return restTemplate;
  }
}