Failed to load resource: the server responded with a status of 400 (Bad Request) Spring JS call to Controller not working

Question

I'm trying to call a controller method that will save my object, but when i try to url to it, it returns http error. I've browsed through some similar problems on SO but no luck. So i wanna ask myself...

Here is my Ajax (for simplicity purposes i renamed the variables):

function addDob() {
        var var1 = $("#var1").val();
        var var2 = $("#var1").val();
        var var3 = {};
     
         
        var3["var3"] = $("#var3").val(); 
        var json = JSON.stringify({
        
           var1 : var1,
           var2 : var2,
           var3 : var3
        });
           console.log(json);
        alert(json);
        $.ajax({
            url: 'add_dob',
            type: 'POST',
            contentType: 'application/json; charset=utf-8',
            dataType: json,
            success: function (data) {
                 console.log(json);
                alert(data.message);
                resetForm();
            },
            error: function () {
              
                alert("Error!");
            }
        });
    }

Here is my controller:

@RequestMapping(value = "/add_dob", method = RequestMethod.POST, produces = "application/json")
@ResponseBody
public Map<String, Object> saveDob(@RequestBody DobavljacWrapper wrapper) {
    Map<String, Object> data = new HashMap<>();
    Dob d = new Dob();
    d.setCountryID(wrapper.getCountryID());
    d.setDobName(wrapper.getDobName());
    d.setYear(wrapper.getYear());

   dobService.save(d);
    data.put("message", "Dob was successfully saved!");
    return data;
}

Any suggestion is welcomed. If i need to insert any more info, just let me know. Cheers! P.S. I had a similar project that works, but my model classes were different, so i suspect there's something to it..

UPDATE 1.0:

I figured out it has a lot to do with the @RequestBody parameter.

That parameter matches the one you are pushing through with your Ajax. Now, I need that parameter to match my object which has the exact attributes I am passing through with Ajax. Somewhere in there i am making a mistake, and i'm not sure what exactly is the right way here...

If i set "@RequestBody String someString" it will return the parameters i pushed with ajax, but i won't be able to access that info with the getters 'cause it's a string. So i need an object to collect those values!

Answer 1

The answer was the Wrapper class. It couldn't assign values to it and threw error because i set attributes to "private". Setting them "public" solved it for me.

Can't believe that was the error...