Calling Java Method from html without using a servlet

Question

I have my index.html that has a certain view, and I want to update this view (without redirecting or reloading the page) by calling a java method, that consumes a w

Answer 1

You can use servlet, but you have to use Ajax to make asynchronous calls to the servlet without reloading the full page.

$.ajax({
    type:"post",
    url: "redirector?operacion=515&id_orden="+id_orden+"&id_acto="+id_acto, 
    dataType: "text",
    success: function(response){
        //Do the stuffs you need with the response here.
    },
    error: function(response,error){
        console.log(response);
        console.log(error);
    }

});

This is an example of ajax call with jquery where "redirector" is the name of my servlet and on my servlet this is the code that I have:

case 515:

    PrintWriter writer = response.getWriter();
    response.setContentType("text/html");
    response.setCharacterEncoding("UTF-8");

    try {
    Integer id_acto = Integer.parseInt(request.getParameter("id_acto"));
    String resultado = consultasBBDD.consultarNivelesPorActo(id_acto);
    writer.print(resultado);

    } catch (Exception e) {
    System.out.println("Error recuperando niveles de exigencia");
    }

    writer.flush();
    writer.close();
   break;

On the dataType attribute of the ajax call you have to specify the type of the response. Also remember that on your servlet you cant do the request.getRequestDispatcher(urlToGo); when you make ajax calls.

Hope this help and sorry for my horrible english!