json - REST with Spring and Jackson full data binding

Question

I'm using Spring MVC to handle JSON POST requests. Underneath the covers I'm using the MappingJacksonHttpMessageConverter built on the Jackson JSON processor and enabled when you use the mvc:annotation-driven.

One of my services receives a list of actions:

@RequestMapping(value="/executeActions", method=RequestMethod.POST)
    public @ResponseBody String executeActions(@RequestBody List<ActionImpl> actions) {
        logger.info("executeActions");
        return "ACK";
    }

I have found that Jackson maps the requestBody to a List of java.util.LinkedHashMap items (simple data binding). Instead, I would like the request to be bound to a List of typed objects (in this case "ActionImpl").

I know this is easy to do if you use Jackson's ObjectMapper directly:

List<ActionImpl> result = mapper.readValue(src, new TypeReference<List<ActionImpl>>() { }); 

but I was wondering what's the best way to achieve this when using Spring MVC and MappingJacksonHttpMessageConverter. Any hints?

Thanks

Answer 1

I have found that you can also work around the type erasure issue by using an array as the @RequestBody instead of a collection. For example, the following would work:

public @ResponseBody String executeActions(@RequestBody ActionImpl[] actions) { //... }