SPRINGMVC returns the difference between Modelmap and new HashMap

I met a hole today.

Usually write interface, NEWHASHMAP, @ResponseBody return JSON object, no problem

@RequestMapping ("url")    public map<string, object> F1 () {        return  New Hashmap<string, object>();    }

It's such a simple interface.

Since this time I need to draw on an interface from a previous project, I copy it directly.

is directly into the Modelmap object, after looking at the feeling there is no need to new a map object, direct transmission on the line.

SPRINGMVC package is very good, consider quite whole, some small lucky.

@RequestMapping ("url")    public  modelmap F1 (Modelmap map) {        return  Map;    }

After copy comes back to the Modelmap object, the postman test returns 404.

Only then know, nothing is Modelmap support default request view return, so there is no corresponding page natural 404.

Take a note, please.

SPRINGMVC returns the difference between Modelmap and new HashMap