Send a message from html to Servlet java using ajax

Question

I have a stupid proplem for send the input from a html page to a servlet using ajax.

Practically I create the message java how I learned, but the servlet doesn't read the input value. I insert my code

<div class="col_9">
    <h1>Ricerca Dataset</h1>
    <div class="form">
        <div class="col_9">
            <div class="col_12">
                <div class="col_5">Cerca:</div>
                <div class="col_6">
                    <input id=query type="text" name="name" />
                </div>
            </div>
        </div>
        <div class="col_3">
            <button id="cerca" class="large">Cerca</button>
        </div>
    </div>
</div>

function cercaNormaleFn() {
    $("#cerca").click(function(e) {
        $("#center").load("ShowResult.jsp", function() {
            var oTable = $('#example').dataTable({
                "processing" : true,
                "ajax" : {
                    url : context + "/CercaServlet",
                    dataSrc : "demo",
                    type : "Post",
                    data : "query=" + $("#query").val(),
                }
            });
            alert(query)
        });
    });

   }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,
        IOException {

    System.out.println(request.getAttribute("data"));
}

Answer 1

You may need to add the attribute to your dataTable function:

"serverSide": true

as dataTables.net Server-side processing explains:

With server-side processing enabled, all paging, searching, ordering etc actions that DataTables performs are handed off to a server

A demo from dataTables.net post demo