HTTP PUT and POST to static JSON file return 404 error

I am trying to build a small AngularJS CRUD type application so I can learn the framework.

My data is stored in static .JSON files. I am using GRUNT to serve my application. (using npm command "grunt serve").

I have created the following two factories in my app.js file, so that I can pick up my data RESTfully using ngResource:

.factory('bookFactory', ['$resource', 
    function($resource) {
    return $resource('api/books/:bookId.json', {}, {
        update: { method: 'PUT', params: {bookId: '@bookId'}, isArray:false }
    })     
}])
.factory('booksFactory', ['$resource',
    function($resource) {
    return $resource('api/books/:bookId.json', {}, {
        create: { method: 'POST', params: {bookId: '@bookId'}, isArray:false },
        query: { method:'GET', params: {bookId:'books'}, isArray:true }
    })
}]) 

The QUERY action is working. I am able to query my books from my JSON file and display them in the browser. However, when I try to use the PUT or CREATE methods, I get a 404 NOT FOUND error...

The way I am calling the PUT action is as follows.

In my view, I have a link with the attribute:

ng-click="updateBook()"

In the controller linked to that view, I have the updateBook function:

$scope.updateBook = function () {
    bookFactory.update({bookId: $scope.book.id});
    $location.path('/book-list');
};

What is causing this problem? Is it possible to modify a JSON file stored locally on my computer if I serve the app through Grunt? If so, what's wrong with my code?

Thanks for your help!