Manually doing what the ModelAttribute annotation does in Spring MVC

Question

I have an action method on a Spring MVC controller that has an argument annotated with @ModelAttribute. However, I don't know at compile time what the type of this parameter will be - I know the abstract base type but not the derived type.

At runtime, I will be able to decide what class I am expecting and I will be able to get a new'd up instance of this class. However, I have no idea what code I should be calling to parse the request data in the same fashion that @ModelAttribute does.

I've looked around and it seems that if i can get a hold of a WebRequestDataBinder I can use that to populate my object, but for that I need a BinderFactory and this is where I kind of get lost.

Can anyone give me some pointers here - or tell me that I am looking at it the wrong way and need to do something else?

Answer 1

you can inject the model itself in your controllers method and access the attribute yourself.

@RequestMapping(...)
public void doStuff(ModelMap model) {
    Object attr = model.get("nameOfAttribute");
    // ...
}