JS實現websocket長輪詢實時消息提示的效果

<%@ page contentType="text/html;charset=UTF-8" language="java"%>
<div class="page-header navbar navbar-fixed-top">
 <div class="page-header-inner">
 <div class="page-logo">
 <a href="<c:url value=" rel="external nofollow" rel="external nofollow" /"/>"><img
 src="<c:url value="/img/logo.png"/>" style="height: 14px" alt="logo"
 class="logo-default" /></a>
 <div class="menu-toggler sidebar-toggler hide"></div>
 </div>
 <a href="javascript:;" rel="external nofollow" rel="external nofollow" class="menu-toggler responsive-toggler"
 data-toggle="collapse" data-target=".navbar-collapse"></a>
 <div class="top-menu">
 <ul class="nav navbar-nav pull-right">
 <li class="dropdown dropdown-alert"><a href="#" rel="external nofollow" rel="external nofollow" 
 class="dropdown-toggle" data-toggle="dropdown"
 data-hover="dropdown" data-close-others="true"> <span
 class="badge pull-left"></span><label class="hidden-sm">報警</label><i
 class="fa fa-bell"></i>
 </a>
 <ul class="dropdown-menu">
 </ul></li>
 <li class="dropdown dropdown-user"><a href="#" rel="external nofollow" rel="external nofollow" 
 class="dropdown-toggle" data-toggle="dropdown"
 data-hover="dropdown" data-close-others="true"> <span
 class="username username-hide-on-mobile">你好，${sessionScope.username}</span>
 <i class="fa fa-angle-down"></i>
 </a>
 <ul class="dropdown-menu">
 <li><a href="javascript:;" rel="external nofollow" rel="external nofollow" id="updatePass"><i
 class="icon-lock"></i>修改密碼</a></li>
 <li><a href="<c:url value=" rel="external nofollow" rel="external nofollow" /logout"/> "><i
 class="icon-key"></i>退出登錄</a></li>
 </ul></li>
 </ul>
 </div>
 </div>
</div>
<div class="clearfix"></div>
<script>
 //toastr.sos(num1)
</script>
<script type="text/javascript"
 src="http://cdn.bootcss.com/jquery/3.1.0/jquery.min.js"></script>
<script type="text/javascript"
 src="http://cdn.bootcss.com/sockjs-client/1.1.1/sockjs.js"></script>
<script type="text/javascript">
 function wsPath() {
 var pathName = window.document.location.pathname;
 var host = window.location.host;
 var projectName = pathName.substring(0,
 pathName.substr(1).indexOf('/') + 1);
 return (host + projectName);
 }
 wsPath = wsPath();
 var websocket = null;
 if ('WebSocket' in window) {
 websocket = new WebSocket("ws://" + wsPath + "/websocket/socketServer");
 } else if ('MozWebSocket' in window) {
 websocket = new MozWebSocket("ws://" + wsPath
 + "/bison/websocket/socketServer");
 } else {
 websocket = new SockJS("http://" + wsPath
 + "/bison/sockjs/socketServer");
 }
 websocket.onmessage = onMessage;
 websocket.onope = onOpen;
 websocket.onerror = onError;
 websocket.onclose = onClose;
 function onOpen() {
 }
 function onMessage(evt) {
 var $uncheckedAlertMenuBtn = $("a.dropdown-toggle", $uncheckedAlertMenu);
 var $uncheckedAlertBadge = $("span.badge", $uncheckedAlertMenuBtn);
 var $uncheckedAlertMenu = $('li.dropdown-alert');
 var $uncheckedAlertList = $('ul', $uncheckedAlertMenu);
 var a = $uncheckedAlertBadge.html();
 $uncheckedAlertBadge.html(Number(a) + 1);
 //判斷報警類型 如果是位置偏移，place+1
 if (evt.data == "1") {
 var count;
 var a = $("#number").html();
 if (a == null) {
 count = 1;
 $uncheckedAlertList
 .prepend('<li class="place-alert"><a href="alert?menuId=274" rel="external nofollow" rel="external nofollow" > <font color="red" id="place-alert">'
 + "位置報警(<font id ='number'>"
 + count
 + "</font>)" + '</font></a></li>');
 } else {
 count = Number(a) + 1;
 $("#place-alert").html(
 "位置偏移(<font id='number'>" + count + "</font>)");
 }
 }
 if (evt.data == "0") {
 var count;
 var a = $("#snum").html();
 if (a == null) {
 count = 1;
 $uncheckedAlertList
 .prepend('<li class="sos-alert"> <a href="alert?menuId=274" rel="external nofollow" rel="external nofollow" ><font color="red" id="sos-alert">'
 + "SOS報警(<font id='snum'>"
 + count
 + ")</font>"
 + '</font></a></li>');
 } else {
 count = Number(a) + 1;
 $("#sos-alert").html(
 "SOS報警(<font id='snum'>" + count + "</font>)");
 }
 }
 }
 function onError() {
 websocket.close();
 }
 function onClose() {
 }
 window.close = function() {
 websocket.onclose();
 }
</script>