EL隐含对象有以下11种：

1.pageContext:取得用户请求或页面信息；

2.pageScope:相当于page.getAttribute(name);

3.requestScope:相当于request.getAttribute(name);

4.sessionScope:相当于session.getAttribute(name);

5.applicationScope:相当于application.getAttribute(name);

6.param:相当于request.getParameter(name);

7.paramValues:相当于request.getParameterValues(name);

8.header:相当于request.getHeader(name);

9.headerValues:相当于request.getHeaders(name);

10.cookie:相当于request.getCookies();

11.initParam:相当于config.getInitParameter(name);

例如：userName:<input type="text" name="userName"/>

　　///获取文本框的值

　　　userName:${param.userName}