Question

My $.getJSON method is calling the servlet but callback function is not working.

this is my js file:

$(document).ready(function() {
$('p').addClass('highlight');
receiveData();
});

function receiveData(){

    alert('receive data');
    $.getJSON('ProcessForm', function(data){alert('hi')});
    }

“Receive data” alert is coming on the screen, as well as call to ProcessForm Servlet is going, But the alert in the callback method is not coming.

This is what I had written in the ProcessForm Servlet

package com.nagarro.web;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.gson.Gson;
import com.nagarro.json.DictionaryList;


public class ProcesFormServlet extends HttpServlet
{

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse response)
            throws ServletException, IOException {

        DictionaryList dictionaryList = new DictionaryList();
        System.out.println("haan ji sir");
        // Write response data as JSON.
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        response.getWriter().write(new Gson().toJson(dictionaryList));
        super.doGet(req, response);
    }

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

        DictionaryList dictionaryList = new DictionaryList();
        System.out.println("haan ji sir");
        // Write response data as JSON.
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        response.getWriter().write(new Gson().toJson(dictionaryList));
        super.doPost(req, response);
    }

}

Anybody having any idea what could be the issue

Answer 1

Is it possible that you’re not returning well-formed JSON? That would cause jquery to not execute the callback code.

If you’re sure you are (run it through a JSON Lint site to double check), make sure you’re specifying Content-type: application/json in the header for the HTTP response