JSTL标签库简介

<!-- 捕获异常 -->
<c:catch var="exception">
<%
int a=1,b=0;
out.print(a/b);
%>
</c:catch>
<c:out value="${exception }"/>

<!-- 建立URL -->
<a href="<c:url value="//index.jsp"/>">哈哈哈</a>
<a href="/index.jsp">哈哈哈</a>

<!-- 使用其他Web应用URL -->
<c:url value="/index.jsp" var="add" context="/MyMessage"/>
<a href="${add }">呵呵</a>

<%
Calendar now=Calendar.getInstance();
Integer hour=new Integer(now.get(Calendar.HOUR_OF_DAY));//获取小时
request.setAttribute("time", hour);
%>
<c:if test="${time>=0&&time<=11 }">
<c:set value="早上好!" var="sayhello"/>
</c:if>
<c:if test="${time>=12&&time<=17 }">
<c:set value="下午好!" var="sayhello"/>
</c:if>
<c:if test="${time>=18&&time<=23 }">
<c:set value="晚上好!" var="sayhello"/>
</c:if>
<c:out value="${sayhello }"/>

<c:choose>
<c:when test="${time>=0&&time<=11 }">
<c:set value="moring" var="sayhello"/>
</c:when>
<c:when test="${time>=12&&time<=17 }">
<c:set value="noon" var="sayhello"/>
</c:when>
<c:otherwise>
<c:set value="night" var="sayhello"/>
</c:otherwise>
</c:choose>
<c:out value="${sayhello }"/>