@RequestMapping(value = "/signup", method = RequestMethod.POST)
    public ResponseEntity<String> signup(@RequestBody Candidat candidat) throws Exception {
        String response = candidatMetier.signup(candidat);

        if (response.equals("username_already_exists"))
            return new ResponseEntity<>("User name already exists", HttpStatus.CONFLICT);
        else if (response.equals("email_already_exists"))
            return new ResponseEntity<>("Email already exists", HttpStatus.CONFLICT);
        else if (response.equals("mailer_error"))
            return new ResponseEntity<>("Cannot signup, reason : Email service is down",
                    HttpStatus.SERVICE_UNAVAILABLE);
        else
            return new ResponseEntity<>("Signup successful", HttpStatus.OK);
    }

.factory('signupService',['$resource',
    function ($resource) {
      return $resource('http://localhost:8080/signup', {}, {
        signup: { method: "POST"}
      });

    }])

signupService.signup({
                  type: "UC",
                  username: $scope.user.username,
                  password: $scope.user.password,
                  email: $scope.user.email
                }).$promise.then(function(data){
                  console.log(data);
                }).finally(function(){
                  $scope.loading = false;
                  $scope.signupSucceful = true;
                  console.log('finished');
                });

SyntaxError: Unexpected token S in JSON at position 0