Tips for using AJAX and JSON to maintain real-time data in JSP pages

After hours of searching, I still couldn't find a simple solution to my problem. I need to make something easy.

I have a Java class that contains a map of "Service" objects along with an integer variable called "lastCustomer". When this value changes, how can I ensure that the data displayed on my page stays updated without needing a refresh?

I know I'm supposed to use AJAX and JavaScript, but I'm not sure where to begin.

EDIT:

I think I may have made some progress, but now I'm stuck on the parsing aspect. Currently, I have a servlet set up to retrieve the data and display it at "/display/something". How can I access this data using jQuery?

In essence, I have a list of dynamic objects that I need to display and update their values.

Also, the JSON string provided by the servlet does not automatically update itself; it requires a manual refresh. I believe I'm overlooking some fundamental concept here.

Here is some code:

@WebServlet("/JsonServices")
public class JsonServices extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {


        Gson gson = new Gson();
        String json = gson.toJson(myClass.services());

        response.setContentType("application/json");
        response.getWriter().println(json); 
    }
}

Answer №1

If you're looking for a way to stay updated when changes occur, consider implementing a long polling solution. This method will notify you as soon as something changes. Alternatively, you can achieve a similar result using AJAX.

 function refreshData(){
      $.ajax({
      url: "serverurl",
      type: "GET"
      success: function(data){
        //You will receive JSON or XML data here
      }
    });
   }

var refreshInterval = setInterval(refreshData, 30 * 1000);//Every 30 seconds
refreshData();

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