使用jQuery Ajax保存Tinymce

I am using Tinymce as an editor in my application. I need the user to be able to save the content from the Tinymce into a MySQL database. I know the backend works fine as I can save content from regular input to the database, but Tinymce is not working properly. The content is being posted to my web application as:

[object Object]

Tinymce init

<script>


tinymce.init({
    selector: "input.form-control",
    plugins: [
        "advlist autolink lists link image charmap print preview anchor",
        "searchreplace visualblocks code fullscreen",
        "insertdatetime media table contextmenu paste", "save"
    ],
    toolbar: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image | save",
    save_enablewhendirty : false,
    save_onsavecallback: function () {var todo = tinyMCE.get('content'); createTodo(todo); countTodos(); console.log(todo)}
});
</script>

This is my function to create the object that Tinymce content is saved to.

function createTodo(text) {
     $.post("/stuffs/" + text)
        .done(function (result) {
            var markup = '<li class="ui-state-default"><div class="checkbox"><label><input type="checkbox" value="" /><p>' + text + '</p></label></div></li>';

            $('#sortable').append(markup);
            $('.add-todo').val('');
        })
        .fail(function (jqXHR, textStatus, errorThrown) {
            alert('Documents cannot be added!');
        })
}

From my console.log, in case it is helpful:

Object { documentBaseUrl: "http://localhost:8080/", settings: Object, id: "content", isNotDirty: true, plugins: Object, documentBaseURI: Object, baseURI: Object, contentCSS: Array[1], contentStyles: Array[4], _eventDispatcher: Object, 54 more… }

And this is present in console.log too

XML Parsing Error: no root element found
Location: http://localhost:8080/stuffs/[object%20Object]
Line Number 1, Column 1:

P.S. my application is in Spring Boot.

UPDATE: I am able to pass HTML content in an alert box using the code below in my save_onsavecallback.

var mce = tinyMCE.get('content'); var todo = mce.getContent(); alert(todo);

However, I get a 405 "Method Not Allowed"

Spring Tool Suite says in the console:

o.s.web.servlet.PageNotFound  Request method 'POST' not supported