angularJs, Spring MVC : how to send data to Spring controller

Question

I'm trying to send an image from my web app to my Spring RestController; but I don't manage to cast Object which I receive.

ANGULARJS - CONTROLLER :

myModule.controller('InscriptionCtrl',function($location, $http){

    var self = this;

    self.credentials = {};

    self.register = function(credentials){

        var FormRegisterDto = credentials ? {
            login : credentials.login, 
            password : credentials.password,
            title : credentials.title,
            name : credentials.name,
            firstname : credentials.firstname,
            age : credentials.age,
            email : credentials.email,
            streetNum : credentials.streetNum,
            streetBister : credentials.streetBister,
            streetName : credentials.streetName,
            city : credentials.city,
            postalCode : credentials.postalCode,
            country : credentials.country
        } : {};

        var fd = new FormData();

        fd.append('data', angular.toJson(FormRegisterDto));
        fd.append("file", this.myImage);

        $http.post(
                '/register-user', 
                fd,
                {
                    transformRequest: angular.identity,
                    headers: {'Content-Type': undefined}
                }
        ).then(
            function(response){
                // success
            },
            function(){
                // error
            }
        );
    };
});

My Spring RestController correctly receive data and file because if I make a print of "data", it is writting : {"login":"aaaaaaaaaa","password":"aaaaaaaaaaaA","title":"M","email":"aaaaaaaaaa@aaaaaaaaaa"}

My issue is that I want to cast Object "data" to my class "FormRegisterDto" which contains properties like "String login", "String password" etc...

My JAVA code :

@RequestMapping(value = "/register-user-blob", produces = "application/json")
public FormRegisterResponseDto registerUserWithBlob(
        @RequestParam(value="file", required=false) MultipartFile file,
        @RequestParam(value="data") Object data){


    FormRegisterRequestDto request = (FormRegisterRequestDto) data; // it doesn't works

    System.out.println(data); // it show {"login":"aaaaaaaaaa","password":"aaaaaaaaaaaA","title":"M","email":"aaaaaaaaaa@aaaaaaaaaa"}

    return new FormRegisterResponseDto();
}

Do you know how to do this ? Thanks ;).

Answer 1

Your Object data, is of type String so you cannot cast it to FormRegisterRequestDto,what you shoud do is serialize the object in front-end converting it to a json string (which it seems to be at this point) and than use Gson google's library like this

Gson gson = new Gson();
FormRegisterRequestDto dto=gson.fromJson(data, FormRegisterRequestDto.class);