jstl 标签

导入Jstl标签库

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

需要导入jstl.jar和standard.jar

c:forEach --> 迭代标签迭代List或Map

<c:forEach var="person" items="${list}">
${person.name }</br>
</c:forEach>

<c:foreach var="entry" items="${map }"> 对map.entrySet()返回的set集合进行迭代
${entry.key } : ${entry.value }
</c:foreach>

<c:forEach var="num" begin="1" end="9" step="1">
${num }
</c:forEach>

<!-- ${status}获取到了一个对象，这个对象包含了当前是第几次迭代 -->
<c:forEach var="str" items="${list }" varStatus="status">
<tr class="${status.count%2==0?'even':'odd'}">
</c:forEach>

c:if --> 判断标签
<c:if test="${user!=null}" var="result"> user存在的话result就为true
欢迎您:${user.username}
</c:if>
${result }

c:out

<c:out value="${data }" default="aaaaa" escapeXml="true"></c:out>

c:set

<!-- c:set可以操作各个域 javabean Map集合 -->
<c:set var="data" value="xxxxxx" scope="page"></c:set>改变data的值；

<c:set property="propertyname" value="valuexx" target="${map }"></c:set>
${map.propertyname }

<c:set property="name" value="uuuuuu" target="${person }"></c:set>
${p.name }

c:catch

<c:catch var="ex">
<%
int x = 1 / 0;
%>
</c:catch>
${ex.message }

c:forTokens --> 分割标签

<c:forTokens var="ss" items="${data1 }" delims=",">
${ss }
</c:forTokens>
data1={"a,b,c,d"}

c:url --> 生成URL

<c:url var="uurrll" value="/example/ind1ex.jsp">
<c:param name="namechina" value="中国"></c:param>
</c:url>
<a href="${uurrll }">hreftext</a>