How do I setup an object mapper with a module for Jackson and Spring

I never used Spring, but I had the same issue using RESTeasy framework. Knowing this, I'll try to give you some answers / direction to search.

To answer one of your questions, ObjectMapper "has to live" whenever you have to deal with a serialization / deserialization into / from json process. For example :

MyObject myObject = new MyObject(); ObjectMapper mapper = new ObjectMapper(); String json = mapper.writeValueAsString(myObject); 

As pointed out in the link you provided, if you want to add a module to your ObjectMapper, you have to add the following line after creating your mapper :

mapper.registerModule(new AnyModuleYouNeed()); 

Now, I'm not a Spring user, but I assume you want this process to be automatic when spring provide its own serialization / deserialization process.

I found this on the web : http://magicmonster.com/kb/prg/java/spring/webmvc/jackson_custom.html

In your case, I think only point 2 and point 3 are usefull for you, and because you don't need to have a custom serializer, but you only need to add a module to your mapper, I think the custom ObjectMapper should look like that :

@Component public class CustomObjectMapper extends ObjectMapper { public CustomObjectMapper() { registerModule(new AnyModuleYouNeed()); } } 

In the web site I pointed to you, they speak alson about an elegant way to register a cusom ObjectMapper for Spring 3.1 users : http://magicmonster.com/kb/prg/java/spring/webmvc/mvc_spring_config_namespace.html

It may be usefull.

Finally, excuse my poor english, and let me know if you had your problem solved.