Parsing Map and String from JSON doesn't work

Question

I am trying to set up my first REST webservice using the spring framework. Before even bothering with the frontend, I want to set up the Requestmapping in the Controller first and I am trying to test this out by using Postman.

I am using postman, set to POST, raw, application/JSON and then the following:

{"attendanceList" : { 
    "Jane Doe": "PRESENT", 
    "John MacDonald": "PRESENT", 
    "Fred Flinstone": "ABSENT"},
"date":"2017-06-01"}

In my Controller I have the following:

@RequestMapping(value = "/post", method = RequestMethod.POST, produces = {MediaType.APPLICATION_JSON_VALUE })
@ResponseBody
public void setAttendence(@RequestBody Map<String, Attendence> attendenceList, String date) {
    //Implementation code
}

However, when I send the above post request to the server, I get a map of size 4:

"attendanceList" -> ABSENT (the default value)
"Jane Doe" ->  PRESENT
"John MacDonald" -> PRESENT
"Fred Flinstone" -> ABSENT

And my String date = null

Why is this not working the way I'm intending it to? What am I doing wrong?

Answer 1

You're telling Spring that the request body, ie the whole JSON, should be parsed to a Map<String, Attendence> . The JSON is clearly not such a map.

It should instead be mapped to a class such as

public class Input {
    Map<String, Attendence> attendanceList;
    LocalDate date;

    // ...
}

And of course, the String date argument, that Spring ignores, should be removed.