Spring MVC - should my domain classes implement Serializable for over-the-wire transfer?

Question

I\'m trying to learn Spring Boot by implementing a simple REST API.

My understanding was that if I need to transfer an object over the wire, that object should impl

Answer 1

The specific examples you have mentioned do not transfer objects over the wire. From the example links I see that the controller methods return a domain object with ResponseBody annotation. Just because the return type of the method is the domain object it is not necessary that the whole object is being sent to the client. One of the handler method in Spring mvc framework internally intercepts the invocation and determines that the method return type does not translate to direct ModelAndView object. RequestResponseBoodyMethodProcessor which handles the return value of such annotated methods and uses one of the message converters to write the return object to the http response body. In the case the message converter used would be MappingJackson2HttpMessageConverter. So if are to follow the same coding style you are not required to implement Serializable for your domain objects.

Have a look at this link for the Http message converters provided by default from spring. The list is quiet extensive however not exhaustive and if requirements arise you can implement your own custom message converter to user as-well.