EL表达式

JSP EL的内置对象
pageContext
pageScope
requestScope
sessionScope
applicationScope
param
paramValues
header
headerValues
cookie
initParam

<%=session.getAttribute("phone") %>
等价于
${sessionScope.phone}

 

设定JSP不使用JSP EL
使用page指令的isELIgnored 属性
<%@ page isELIgnored="true" %>

或者修改web.xml
<web-app...>

<jsp-config><jsp-property-group><url-pattern>*.jsp</url-pattern><el-ignored>true</el-ignored></jsp-property-group></jsp-config>
</web-app>

<%session.setAttribute("username","SunWukong"); %>

${requestScope.username }${sessionScope.username }${applicationScope.username }${pageScope.username }${requestscope["username"]}${username} <% User user = new User();Profile p = new Profile();p.setEmail("[e-mail]");Map<String,String> phone = new HashMap<String,String>();phone.put("office","12345678");p.setPhone(phone);Address address = new Address();address.setCity("深圳");Address[] addresses = {address};p.setAddress(addresses);user.setProfile(p); %>

<tr> <td>/${user.profile.phone.office}</td> <td>${user.profile.phone.office}</td> </tr> <tr> <td>/${user["profile"]["phone"]["office"]}</td> <td>${user["profile"]["phone"]["office"]}</td> </tr> <tr> <td>/${user.profile.address[0].city}</td> <td>${user.profile.address[0].city }</td> </tr> <tr> <td>/${user["profile"]["address"][0]["city"]}</td> <td>${user["profile"]["address"][0]["city"]}</td> </tr>

<tr><td>你的性别:</td><td> <select name="gender"> <option>男</option> <option>女</option> <option>未知</option> </select></td></tr><tr><td valign="top">你喜欢的体育运动：</td><td> <input type="checkbox" name="sport" value="足球">足球 <input type="checkbox" name="sport" value="游泳">游泳 <input type="checkbox" name="sport" value="跑步">跑步 </td></tr> <tr> <td>/${param.gender}</td> <td>${param.gender}</td> </tr> <tr> <td>/${param["gender"]}</td> <td>${param["gender"]}</td> </tr> <tr> <td>/${paramValues.sport[1]}</td> <td>${paramValues.sport[1]}</td> </tr>

用于Cookie中

<% response.addCookie(new Cookie("username","deng")); %> <table border="1"> <tr> <td><b>EL表达式</b></td> <td><b>输出结果</b></td> </tr> <tr> <td>/${cookie["username"].value}</td> <td>${cookie["username"].value}</td> </tr> <tr> <td>/${cookie.username.value}</td> <td>${cookie.username.value}</td> </tr></table>

还可以用于web.xml中的初始参数中

<context-param> <param-name>deng</param-name> <param-value>sheng</param-value> </context-param>

<tr> <td>/${initParam.deng}</td> <td>${initParam.deng}</td> </tr> <tr> <td>/${initParam["deng"]}</td> <td>${initParam["deng"]}</td> </tr>