jQuery AJAX完成未执行

Question

$('#loginForm').submit(function(e){

        var $inputs = $(this).find("input");
        var serializedData = $(this).serialize();   
        $inputs.prop("disabled", true);

        var request = $.ajax({
            url: "myurl",
            dataType: "json",
            type: "GET",
            data: serializedData,
        });

        request.done(function (response, textStatus, jqXHR){
            $('#loginMessage').text('GOOD');
        });

        request.fail(function (jqXHR, textStatus, errorThrown){
            $('#loginMessage').text('Some error occured. Please try again');
            console.error("The following error occured: ",errorThrown,jqXHR);
        });

        request.always(function () {
            $inputs.prop("disabled", false);
        });
        // prevent default posting of form
        e.preventDefault();         
    });

I am new to jquery and in the above code .done block is not executing and firebug console display this message :-

GET myurl?userID=aman&password=aman 200 OK 37ms jquery....min.js (line 2)

The following error occured: (an empty string) Object { readyState=0, status=0, statusText="error"}

Server Side Scripting

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("userID");
        String password = request.getParameter("password");
        System.out.println("GET");
        response.setContentType("application/json");
        PrintWriter out = response.getWriter();
        Gson gson = new Gson();
        if(username.equals("aman") && password.equals("aman")){
            out.println(gson.toJson(new Boolean("true")));
        }else{
            out.println(gson.toJson(new Boolean("false"))); 
        }
        out.close();
    }

Answer 1

The issue likely is you aren't sending complete JSON. I output the result from

out.println(gson.toJson(new Boolean("true")));

and all you get is the word true. Try changing it to something like this.

HashMap<String, Boolean> hm = new HashMap<String, Boolean>();
hm.put("success", true);
out.write(gson.toJson(hm));

Running that I got {"success":true} which is valid JSON.

Answer 2

Probably done is not called because fail is called instead. Since the http request itself seems to have worked, another possible problem is that it did not return proper json content, whereas the reply is interpreted as such (because of dataType: "json").

So, you should investigate about what content the server is returning.

Answer 3

I don't know why, but sometimes firebug breakpoints give the impression that the code in request.done() is not executed. Maybe it is simply channeled to the console.

Try testing your code without breakpoints in firebug.