java web中,内部js代码如何获取服务器后台的变量呢?
根据jsp页面使用的标签不同有一下几种情况:
(1)页面使用EL表达式,使用spring MVC
内部js代码:
alert("222:${sessionScope.practiceWay}"); var practiceWay=String("${sessionScope.practiceWay}");
(2)页面使用struts标签
var length=Number("<s:property value="list.size" />"); alert("length:"+length); var isEdit = "<s:property value="isEdit" />"; var id = "<s:property value="goods.id" />"; var supermarkets_size = Number("<s:property value="supermarkets.size" />");
(3)页面使用jstl标签:
var sum_question=Number("${fn:length(studentPages.list)}");
错误的做法:
var length=Number("<s:property value=\"list.size\" />");
在js外部文件中写<%=com.dict.Constant2.COOKIE_KEY_PASSWORD %> 是不对的
$(function(){ var $username=$("#username"); var $password=$("#password"); var $issavePasswd=$("input[name=issavePasswd][type=checkbox]"); var usernameVal=null; var passwordVal=null; usernameVal=com.whuang.hsj.getCookie("<%=com.dict.Constant2.COOKIE_KEY_USERNAME %>"); passwordVal=com.whuang.hsj.getCookie("<%=com.dict.Constant2.COOKIE_KEY_PASSWORD %>"); if(com.whuang.hsj.isHasValue(usernameVal)){ $username.val(usernameVal); } if(com.whuang.hsj.isHasValue(passwordVal)){ $password.val(passwordVal); com.whuang.hsj.setSelectedCheckbox($issavePasswd.get(0)); } });
总结:在js 代码中可以直接写JSP代码,上述代码中,不要对引号转义。
示例:
<?xml version="1.0" encoding="UTF-8" ?>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://"
+ request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<base href="<%=basePath%>">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Insert title here</title> <script type="text/javascript"
src="<%=path%>/static/js/Module.js"></script>
<script type="text/javascript" src="<%=path%>/static/js/common_util.js"></script>
<script type="text/javascript" src="<%=path%>/static/js/test.js"></script>
<script type="text/javascript" >
window.onload = function() {
var isEdit = "${isEdit }";
if (isEdit != null && isEdit == "yes") {
//alert("edit");
var inputform = com.whuang.hsj.$$one("inputform");
//modify the target action fo form
inputform.action = "osType/update";
var titleSpan = document.getElementById("titleSpan");
//alert(titleSpan);
titleSpan.innerHTML = "edit os";
var hidden_div = document.getElementById("hidden_div");
hidden_div.innerHTML = '<input type="hidden" name="id" value="${os.id }" ></input>';//id of goods for update
var osTypeName=com.whuang.hsj.$$one("name");
osTypeName.value=String("${os.name}");
}
//alert("222:${sessionScope.practiceWay}");
var practiceWay=String("${sessionScope.practiceWay}");
alert("333:"+practiceWay);
a();
};
</script>
</head>
<body>
<center>
<h1><span id="titleSpan">add </span> </h1>
<input type="hidden" value="${sessionScope.practiceWay}" name="hidpracticeWay" />
<a href="javascript:history.go(-1)" >return </a> |
<a href="index.jsp" >index</a> | <a href="osType/viewAll">view all</a>
<form action="osType/save" name="inputform" >
<table>
<tr>
<td>os name:</td>
<td><input type="text" name="name" /></td>
</tr>
<tr>
<td colspan="2" ><input type="submit"
value=" o k " id="submit_btn" /></td>
</tr>
</table>
<div id="hidden_div"></div>
</form>
</center>
</body>
</html>