jsp（部分）;MVC;EL表达式;JSTL

contentType:等同于response.setContextType()

import：导包

errorPage：当前页面发生异常后，会自动跳转到指定的错误页面

isErrorPage：标识当前页面是否是错误页面

<%@include file="top.jsp"%>

&nbsp;&lt;%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %&gt;<br> prefix:前缀，自定义的

变量名&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 真实类型&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;作用<br>* pageContext&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; PageContext&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;当前页面共享数据，还可以获取其他八个内置对象<br>* request&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;HttpServletRequest&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 一次请求访问的多个资源（转发）<br>* session&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;HttpSession&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 一次会话的多个请求间<br>* application&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;ServletContext&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;所有用户间共享数据<br>* response&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; HttpServletResponse&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;响应对象<br>* page&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Object&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 当前页面（Servlet）的对象 相当于this<br>* out&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;JspWriter&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 输出对象，数据输出到页面上<br>* config&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ServletConfig&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Servlet的配置对象<br>* exception&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Throwable&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;异常对象

耦合性低，方便维护，可以利用分工协作

重用性高

使得项目架构变得复杂，对开发人员要求高

算术运算符： + - *&nbsp; /(div)&nbsp; %(mod)

比较运算符：&gt;&nbsp; &nbsp;&lt;&nbsp; &nbsp;&gt;=&nbsp; &nbsp;&lt;=&nbsp; &nbsp;==&nbsp; &nbsp;!=

逻辑运算符：&amp;&amp;(and) ||(or) !(not)

空运算符：empty

语法：

对象：${域名称，键名，属性名}

list集合：${域名称.键名[索引]}

Map集合

el表达式中有11个隐式对象

pageContext：

test为必须属性，接收boolean表达式

如果表达式为true，则表示if标签内容，如果为false，则不显示标签体内容

一般情况下，test属性值会结合el表达式一起使用

c:if标签没有else情况，想要else情况，则可以再定义一个c:if标签

相当于switch声明

相当于case

相当于default

for(int i = 0; i&lt; 10;i++){<br><br> }

属性：

List&lt;User&gt; list;<br> for(User user:list){<br><br> }

属性：