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：
Js代码
- alert("222:${sessionScope.practiceWay}");
- var practiceWay=String("${sessionScope.practiceWay}");
（2）页面使用struts标签
Js代码
- 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：
Js代码
- 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
Js代码
- $(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：
Html代码
- <?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>
