html显示长度较大的数据时的处理方法

<a title="${siteBoardInfoList.boardUrl}">
<c:if test="${fn:length(siteBoardInfoList.boardUrl) >= 40}">
${fn:substring(siteBoardInfoList.boardUrl,0,20)}......${fn:substring(siteBoardInfoList.boardUrl,fn:length(siteBoardInfoList.boardUrl)-21,fn:length(siteBoardInfoList.boardUrl))}
</c:if>
<c:if test="${fn:length(siteBoardInfoList.boardUrl) < 40}">
${siteBoardInfoList.boardUrl}
</c:if>
</a>