EL表达式+JSTL

cookie的保存和获得

保存

<%
  		Cookie c1 = new Cookie("uname","abcd");
  		c1.setMaxAge(5*60);
  		
  		Cookie c2 = new Cookie("uinfo","xyz");
  		c2.setMaxAge(5*60);
  		
  		//保存cookie
  		response.addCookie(c1);
  		response.addCookie(c2);
  	%>
           

获取

//jsp获取
	<%
  		String v1 = "";
  		String v2 = "";
  		
  		Cookie[] cks = request.getCookies();
  		for(int i = 0 ;i < cks.length ;i++){
  			if("uname".equals( cks[i].getName())) v1 = cks[i].getValue();
  			if("uinfo".equals( cks[i].getName())) v2 = cks[i].getValue();
  		}
  		
  	%>
  	<br/><br/>
  	ck1:<%=v1 %><br/>
  	ck2:<%=v2 %><br/>
    <hr/>
	EL表达式获取
    ck1 : ${cookie.uname.value }<br/>
    ck2 : ${cookie.uinfo.value }<br/>
           

获取header

//jsp
	<%
  		Enumeration keys = request.getHeaderNames();
  		while( keys.hasMoreElements() ){
  			String k = (String)keys.nextElement();
  			out.print("<br/>"+ k +"::"+request.getHeader( k ));
  		}
  	%>
  	<hr/><hr/>
  	1.<%=request.getHeader("user-agent") %><br/>
  	2.<%=request.getHeader("accept-language") %><br/>
  	<hr/><hr/>
	EL表达式
  	1.${header["user-agent"] }<br/>
  	2.${header["accept-language"] }<br/>
           

其它符号

<%
   		pageContext.setAttribute("fff", new Users(300,"周瑜",1.82));
   		pageContext.setAttribute("sss", new Users(301,"太史慈",1.96));
   	%>
         个子高: ${fff.uheight > sss.uheight ? fff.uname : sss.uname }<br/>
         个子高2: ${fff.uheight gt sss.uheight ? fff.uname : sss.uname }<br/><br/>
         
         名字相等吗 : ${ fff.uname == sss.uname ? "" :"不" }相等<br/>
         名字相等吗2 : ${ fff.uname eq sss.uname ? "" :"不" }相等<br/><br/>
    
         相等吗 : ${ fff.uname != sss.uname ? "不" :"" }是一个人<br/>     
         相等吗 : ${ fff.uname ne sss.uname ? "不" :"" }是一个人<br/><br/> 
         
    <%
    	pageContext.setAttribute("ttt", "asdfasdf");
    	pageContext.setAttribute("qqq", "");
    %>     
          存在或为空1: ttt ${ empty ttt ? "无":"有" }数据<br/> 
          存在或为空2: qqq ${ empty qqq ? "无":"有" }数据<br/> <%-- qqq!=null && qqq.size>0 --%>
          存在或为空3: www ${ empty www ? "无":"有" }数据<br/>
           

JSTL

JSP Standard Tag Library

jsp引入

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

定义

<c:set var="a1" value="aabbcc"/>
   	<c:set var="a2" value="xx<font color='red'>yy</font>zz"/>
   	<c:set var="a2" value="${upd}" scope="request"/>
    1.${a1}<br/>
    2.${a2}<br/>
    3.${requestScope.a2}<br/>
           

输出

输出:<br/>      
    0.<c:out value="a1"/><br/>
    1.<c:out value="${a1}"/><br/>
    2.<c:out value="${a2}" escapeXml="false"/><br/>
    3.<c:out value="${a2}"/><br/>
    3.<c:out value="${requestScope.a2.uname}"/>--${requestScope.a2.uname}<br/>
           

删除

删除:<br/>
   	<c:remove var="a2"  scope="page"/>
   	1.${a1}<br/>
    2.${a2}<br/>
    3.${requestScope.a2}<br/>
           

异常

异常:<br/> 
   	<c:catch var="haha"> 
   	 1. ${requestScope.a2.uname1} 
   	</c:catch>
           

静态/动态引入

静态/动态引入:<br/> <!-- jsp代码拷贝到引入的位置     一起翻译成 java文件，编译成class,运行返回html代码 -->
   					 <!-- 各个jsp生成的html代码拷贝到引入的位置  -->		
   	<table width="200" height="150" border="1">
   		<tr>
   			<td><%@ include file="/myDiv1.jsp" %></td><!--静态引入-->
   			<td>2</td>
   			<td>3</td>
   		</tr>	
   		<tr>
   			<td><jsp:include page="/myDiv1.jsp"/></td><!--动态引入-->
   			<td>
   				<jsp:include page="/myDiv1.jsp">
   					<jsp:param value="100" name="tp"/><!--动态引入-->
   				</jsp:include>	
			</td>
   			<td>6</td>
   		</tr>
		<tr>
   			<td>7</td>
   			<td><c:import url="/myDiv1.jsp"/></td><!--动态引入-->
   			<td><c:import url="/myDiv1.jsp">
   					<c:param name="tp">210</c:param>
   				</c:import>	
   			</td>
   		</tr>
   	</table>
           

路径

路径:
   	<c:url var="aa" value="http://www.baidu.com"/>
   	<c:url var="bb" value="http://www.baidu.com">
   		<c:param name="id">50</c:param>
   		<c:param name="id" value="${a1}"></c:param>
   	</c:url>
   	
   	${aa}--${bb}
           

if

<%	
  	
  		pageContext.setAttribute("upd", new Users(400,"陈宫",173));
  	
  		List<Users> ulist =new ArrayList<Users>();
		ulist.add( new Users(100,"诸葛亮",1.84));
		ulist.add( new Users(101,"关羽",2.12));
		ulist.add( new Users(102,"张飞",1.98));
		ulist.add( new Users(103,"刘备",1.74));
		
		pageContext.setAttribute("fff", ulist);
  	%>
	if:<br/>
  	<c:if test="${ empty upd }" var="ret">
  		没有要修改的对象
  	</c:if>
  	<c:if test="${!ret}">
  		有有有
  	</c:if>
           

swith

swith:<br/>
  	<c:choose>
  		<c:when test="${upd.uheight le 170}">小兵</c:when>
  		<c:when test="${upd.uheight le 180}">吾长</c:when>
  		<c:otherwise>大将</c:otherwise>
  	</c:choose>
           

for

for:<br/>
  	<c:forEach items="${fff}" var="f" varStatus="st"><!-- for( Users f : fff) -->
  		${st.index}--${f.uname}--${f.uheight}<br/>
  	</c:forEach>
	<c:forTokens items="111,222,333,444#555,666" delims="," var="s">
  		${s}<br/>
  	</c:forTokens>
	<c:forEach begin="1" end="10" step="2" var="x"> <!-- for( int i = 1 ; i <=10 ; i+=2) -->
  		${x}
  	</c:forEach>
	
           

fmt标签

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

<%
	   		Date d1 = new Date();
	   		pageContext.setAttribute("ttt", d1);
	   		
	   		SimpleDateFormat fmt = new SimpleDateFormat("yyyy年MM月dd日 hh时mm分ss秒SSS毫秒  E");
	   	%>
	   1.<%=d1 %><br/>
	   2.<%=fmt.format(d1) %><br/>
	   <br/><br/>
	   3.<m:formatDate value="${ttt}" pattern="yyyy年MM月dd日 hh时mm分ss秒SSS毫秒  E"/> 
	   
	   <hr/>
	   4.<m:formatNumber value="32454245.24545" pattern=",###.####"/><br/>
	   5.<m:formatNumber value="32454245.24" pattern=",###.0000"/><br/>
	   6.<m:formatNumber value="1.64" pattern=",###.0000"/><br/>
	   7.<m:formatNumber value="1.64" pattern=",000.0000"/><br/>
           

functions标签

<%
  		pageContext.setAttribute("xyz", "aabbccdd");
  	%>
  	1.${fn:substring(xyz,2,4) 	}<br/>
  	2.${fn:substring(xyz,4,-1) 	}<br/>
   	3.${fn:replace(xyz,"bc","海洋") }<br/>
   	4.${fn:toUpperCase(xyz)		}