java 跨域-利用jsonp

/**
     * 前端首页跳转后台
     */
    @RequestMapping("WebIndex.get")
    @ResponseBody
    public String WebIndex(HttpServletRequest request,HttpServletResponse response){
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        //数据
        List studentList = new ArrayList<>();
        studentList.add("wu1");
        studentList.add("wu2");
        studentList.add("wu3");
        String result=new Gson().toJson(studentList);
        //前端传过来的回调函数名称
        String callback = request.getParameter("callback");
　　　　　String callback2 = request.getParameter("name");//获得前端的参数
        System.out.println(callback2);
        //用回调函数名称包裹返回数据，这样，返回数据就作为回调函数的参数传回去了
        result = callback + "(" + result + ")";
        logger.debug("前端首页跳转后台");
        return result;
    }

<script>
        window.onload=function(){
            //url格式：地址？openid=密码&nickname=账号，split进行分割
            var url = decodeURI(window.location.href);
            var argsIndex = url.split("?openid=");
            var argsIndex2 = argsIndex[1].split("&nickname=");
            var openid = argsIndex2[0];
            var nickname = argsIndex2[1];
            alert("openid="+openid+"---"+"nickname="+nickname)
            var ip = getip();
            ip += "WebIndex.get";
            var reqBody = {
                username: "id",
                password: "pwd"
            };
            var sendJson = {
                body: reqBody
            }
             $.ajax({
                    url: ip,
                    type: "GET",
                    dataType: "jsonp", //指定服务器返回的数据类型
                    data:{
                        ‘name‘:‘zuzuzu‘
                    },
                    success: function (data) {
                        var result = JSON.stringify(data); //json对象转成字符串
                        alert(result);
                    }
                });
        }
        //获得Ip地址
        function getip() {
            if(window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari
                xmlhttp = new XMLHttpRequest();
            } else { // code for IE6, IE5
                xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
            }
            xmlhttp.open("GET", "../ip.xml", false);
            xmlhttp.send();
            xmlDoc = xmlhttp.responseXML;
            var ip = xmlDoc.getElementsByTagName("root")[0].childNodes[0].nodeValue;
            return ip
        }
    </script>