fn去除空格後，在截取字符串

<c:set var="str" value=" This is a TEST String   " />

	 Before trim = ${fn:length(str)}<br/>

<c:set var="str1" value="${fn:trim(str)}" />

	 After trim = ${fn:length(str)}<br/>

<c:choose>
<c:when test="${fn:length(str1)>16}">${fn:substring(str1,0,16)}...</c:when>
<c:otherwise> This is a TEST String </c:otherwise>

</c:choose>

  Now string is = ${str}

輸入的結果：

Before trim = 24
After trim = 21
Now string is = This is a TEST String

引入標籤：

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