Ajax请求未传递给控制器(Ajax request not passed to controller)

 我向控制器发送了一个AJAX请求。 这个开发在JSP和Spring环境中完成。 SimpleFormController被我正在使用的控制器覆盖。 使用JavaScript我创建对象并发送请求。 此请求未传递给控制器​​。 如果您对此问题有任何疑问，请帮助我。 
 
 发送请求的JavaScript代码。 
 
function getStates(){
    var httpRequest;
    var country = document.getElementById('countryName');
    alert(country);
    var url = '/developer/register.htm';

    url = url + (url.match(new RegExp('\\?')) ? '&isAjax=true' : '?isAjax=true');

     if (window.ActiveXObject)
     {
         httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
     }
     else if (window.XMLHttpRequest)
     {
         httpRequest = new XMLHttpRequest();
     }

     httpRequest.open("GET", url, true);
     httpRequest.onreadystatechange = function() {processRequest(); };
     httpRequest.send(null);
}

function processRequest() {
    if(httpRequest.readyState == 4){
        alert("inside ready state");
        var response = http.responseText;
        document.getElementById('states').innerHTML = response;
    }
}
 
 变量url以我在调度程序servlet中提到的方式给出。 
 
 浏览器在processRequest（）函数中显示错误 ，告知未定义httpRequest。 但是，我在前面的行中没有得到这个错误 ，我在getStates（）函数中使用了这个对象。 如果有人对此有所了解，请帮我解决这个问题。 在此先感谢并感谢您的支持。 

I send an AJAX request to my controller. This development done in JSP and Spring environment. SimpleFormController is overridden by the controller I'm using. 
 
Using JavaScript I create the object and send the request. this request is not getting passed to controller.
 
JavaScript code which send the request.
 
function getStates(){
    var httpRequest;
    var country = document.getElementById('countryName');
    alert(country);
    var url = '/developer/register.htm';

    url = url + (url.match(new RegExp('\\?')) ? '&isAjax=true' : '?isAjax=true');

     if (window.ActiveXObject)
     {
         httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
     }
     else if (window.XMLHttpRequest)
     {
         httpRequest = new XMLHttpRequest();
     }

     httpRequest.open("GET", url, true);
     httpRequest.onreadystatechange = function() {processRequest(); };
     httpRequest.send(null);
}

function processRequest() {
    if(httpRequest.readyState == 4){
        alert("inside ready state");
        var response = http.responseText;
        document.getElementById('states').innerHTML = response;
    }
}
 
Variable url is given in the way how I have mentioned in dispatcher servlet.
 
The browser shows an error in processRequest() function telling that httpRequest is not defined. but, I don't get this error in the previous lines. I use this object in getStates() function.

原文：https://stackoverflow.com/questions/8118690