how can pass array to java servlet

Question

On my jsp, this is my code :

 $('.save').on("click",function(){    
    var array = $.map($('table tr'), function (val, i) {
            var obj = {}, inputs = $(val).find('td input:not(:hidden)');
            obj[inputs.filter(':first').val()] = $.map(inputs.not(':first'), function (val, i) {
                return val.value;
            });
            return obj;
        });
        var data = JSON.stringify(array);
        $.post("Controller.html", data, function(response) {
        /// i dont know what to put here,so i think this where i get trouble with
     });
    });

but still data is null when i check on servlet.

this is my servlet :

 protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String data=request.getParameter("data");
        if (data== null) {
            System.out.println("null");
        }
        RequestDispatcher view = request.getRequestDispatcher("/page.jsp");
        view.forward(request, response);
    }

fiddle here

Answer 1

First you need to send the data, you can use an ajax post method:

$.post("yourservlet", data=JSON.stringify(array), function(response) {
    // handle response from your servlet.
    alert(response)
});

In servlet, you retrieve the data with the command:

String data=request.getParameter("data");

Then you need to parse the json, you can use a library like JSON simple:

Object obj = JSONValue.parse(data);
JSONArray array = (JSONArray) obj;

Or you can manually parse it. Based on your code, your json string will look like this:

data = "[{'orange':['1.00','5']},{'apple':['2.00','5']}]";

You can use split() method or StringTokenizer to separate each object, but you should write your own parser method, for this you can find many tutorials on google.

Answer 2

Javascript is in client-side. And java servlet is for server-side.

You must use ajax to make a call from client-side to your servlet.