ajax调用servlet并重定向到jsp

Question

这里在下面的代码中我想通过ajax调用一个servlet，然后我将数据从servlet重定向到jsp.ajax调用servlet工作正常但问题是重定向到jsp页面没有显示在浏览器和同一个jsp中当我使用没有ajax的javascript代码时显示页面。

jsp文件中的javascript ajax代码：

function generate(){
...
...
 var url="RedirectServlet";
 var ajax=new AJAXInteraction(url,"RedirectServlet");
 var param    ="FD="+FD+"&TD="+TD+"&actionid="+status+"&usercode="+usercode+"&action=reports"+"";
 ajax.send(param);

....
 }
 function AJAXInteraction(url, actionType) {
     this.url = url;

     var req = init();
   var actionRequested = actionType;
     req.onreadystatechange = processRequest;      
    function init() {
        if (window.XMLHttpRequest) {
            return new XMLHttpRequest();
        } else if (window.ActiveXObject) {
            return new ActiveXObject("Microsoft.XMLHTTP");
        }
     }

     function processRequest () {
        if (req.readyState == 4) {
            if (req.status == 200) {                                
                if(actionRequested=="TestDelegation") {                     
                    PostProcess1(req.responseXML);
                }

            }
        }
     }
     this.send = function(param) {
        req.open("POST", url, true);

        req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

        req.send(param);


     }
}//end of AJAX Interaction object.

Servlet代码：

  protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
        {
    System.out.println("calling doPost() ");

    response.setContentType("text/html;charset=WINDOWS-1256");
    String action=request.getParameter("action");
    System.out.println(action);

    if(action.equals("reports")){
        System.out.println("inside reports");



        //Getting values from Reports_arb.jsp
        String Fromdate=request.getParameter("FD");
        String Todate=request.getParameter("TD");
        String status=request.getParameter("actionid");
        String usercode=request.getParameter("usercode");

        //placing given values in a session 


        request.setAttribute("FD", Fromdate);
        request.setAttribute("TD", Todate);
        request.setAttribute("actionid", status);
        request.setAttribute("usercode", usercode);


        //Redirecting to showReport_arb.jsp
        //response.sendRedirect("showReport_arb.jsp");

          ServletContext sc = getServletContext();
            sc.getRequestDispatcher("/sample.jsp").forward(request, response); 

Answer 1

您需要了解以下事实：当您从ajax发送http请求时，这意味着您在单独的线程中而不是在主线程（您发送请求的页面本身）中发送请求。 因此，servlet上的重定向不会反映在客户端。 为了实现这一点，请将要重定向的URL作为对请求的响应发送回来，并且在ajax的成功方法上只需使用java脚本window.location（URL）;

在servlet

JSONObject jobj = new JSONObject()
String urlToRedirect = "test.jsp";
jobj.put("url",urlStr);
response.getWriter().write(jobj.toString());

在客户端

$.ajax({
                url: 'servletName',
                data: {
                    userID: selectedID
                },
                type: 'post',
                success: function(data){
                  window.location = data.url;
                } 

            });

Answer 2

不使用创建request和response对象，而是使用jquery Ajax 。 它使用起来非常简单。

 /* Send the data using post and put the results in a div */

 $.ajax({
  url: "/YourServlet",
  type: "post",
  data: values,
  success: function(){
      alert("success");
       $("#result").html('submitted successfully');
  },
  error:function(){
      alert("failure");
      $("#result").html('there is error while submit');
  }   
});