Passing Base64 string to POST REST Service

Hi all,

For a few weeks now I've been struggling to pass a base64 string to a Mendix POST REST service in JQuery. I've looked at many sources for help on this, and although progress has been made, I just keep end up getting stuck. You can imagine my frustrations.

Here is the most refined version of the code I'm using to send the information:

$.ajax({
     type: 'POST',
     contentType: 'application/json',
     url: 'http://localhost:8080/rest/postdata/',
     data: {
         title:'Test from AJAX',
         file:base64Str,
     },
     dataType: 'text',
     success: function(data, status){
         alert(data);
         return false;
     }
}).fail(function(){
    alert('failed');
});

NOTE: base64Str is a variable that holds a file encoded in base64.

The .fail function is being invoked when the AjAX call returns. The error I'm receiving in the Browser Console is: XMLHttpRequest cannot load http://localhost:8080/rest/postdata/. Response for preflight has invalid HTTP status code 405.

I've tried researching this error but to no avail. Has anyone ever seen this error, or knows of a way to fix it? I'll appreciate any leads I can get on this. Thanks!

There are other questions I've asked on the forum throughout my journey on this.

1. The answer to my initial post indicated that the base64 string cannot be passed on the URL because of its size. So, I should use a JSON payload to pass that in. This I haven't been able to accomplish to date.
2. My second post spoke specifically to the JSON payload. I was pointed to this post on StackOverflow as a reference. I then searched for the JQuery equivalent and landed here; I'm here to this day. I've tried implementing what I've gathered from both posts, but alas, without luck.

I really need help here!