Error: JQuery and AJAX

I am working with jquery and servlet in java and trying to connect to a method sends me the following error.

  

link : Response to   preflight request does not pass access control check: The   'Access-Control-Allow-Origin' header has a value 'null' that is not   equal to the supplied origin. Origin 'null' is therefore not allowed   access.

This is my method to connect:

$.ajax({
        type: "POST",
        url: "http://localhost:8080/AtnMedicaWeb/atencion/prueba",
        headers: {"Content-Type": "application/json", "Accept": "application/json", 'Access-Control-Allow-Origin' : 'http://localhost:8080'},
        success: function(response){
        },
        failure: function(){
            //location.href = "index.html";
        }
    });