Java Web EL、JSP、Servlet变量

EL   11                JSP   9                                Servlet  

JSP类别
pageContext             pageContext                              *


作用域
pageScope              pageContext.getAttribute()                *
requestScope           request.getAttribute()                   HttpServletRequest.getAttribute() 
sessionScope           session.getAttribute()                   HttpSession.getAttribute()
applicationScope       application.getAttrribute()              ServletContext.getAttribute()

参数相关
param                 request.getParameter()                    HttpServletRequest.getParameter()
paramValues           request.getParameterValues()[返回数组]    HttpServletRequest.getParameterValues()
header                request.getHeader()                       HttpServletRequest.getHeader()   
headerValues          request.getHeaderValues()[返回数组]       HttpServletRequest.getHeaderValues()
cookie                request.getCookies()[返回数组];           HttpServletRequest.getCookies()


initParam             application.getInitParameter()            ServletContext.getAttribute()

${requestScope.contextPath }  ====request.getAttribute("contextPath");
${pageContext.request.contextPath}  =====pageContext.getRequest().getContextPath()

<%
pageContext.setAttribute("order", 1);
request.setAttribute("order", 2);
session.setAttribute("order", 3);
application.setAttribute("order", 4);
%>

${order}    page-->request-->session-->application 从最小范围开始找找到即停止

c:out escapeXml 是否转义 true 转义（> <）  false 不转义

<c:set target='${user}' property='uuid' value='1111'></c:set>    javaBean赋值
<c:set var='aaa' value="11111" scope="request"/>                 给一个变量赋值


<c:forEach    varStatus="status"    index 当前索引  count 列表大小  first 是不是第一个 last是不是最后一个


<c:url    当禁用掉cookie时 进行URL重写


<c:redirect  不需要上下文  上下文相对地址


core
数据标签  out  set  remove

控制标签  forEach  forTokens if  choose

其他标签  url  redirect 

fmt
<%@taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/format" %>
<fmt:formatDate value="${date}" pattern="yyyy-MM-dd"/>

fn
  <%@taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>

1、${fn:contains("1111", "1") }   第一个字符串是否包含第二个字符串
2、fn:containsIgnoreCase(string, substring)
3、fn:endsWith(string, suffix) → boolean   测试时有问题
4、fn:escapeXml(string) → String
5、fn:indexOf(string, substring) → int
6、${fn:join(paramValues.type, ",")}
7、fn:length(input) → integer
8、fn:replace(inputString, beforeSubstring, afterSubstring) → String
9、fn:split(string, delimiters) → String[]
10、fn:startsWith(string, prefix) → boolean
11、fn:substring(string, beginIndex, endIndex) → String
12、fn:trim(string) → String
13、fn:toLowerCase(string) → String
14、fn:toUpperCase(string) → String