怎么样在jstl中判断list是否包含某个值？

<a id="aHref_${device[0]}" onclick='addSelectDeviceId(${device[0]})'>
<c:set var="iscontain" value="false" /> 
<c:forEach items="${sessionScope.SelectDeviceIdsList}" var="map">
<c:if test="${map.key eq device[0]}">  
<c:set var="iscontain" value="true" /> 
 </c:if> 
</c:forEach>

<c:if test="${iscontain}">
<img id="sign_${device[0]}" name="sign_${device[0]}" 
 src="images/expantion/ok_sign.png"/>
<span style="white-space:pre"></span></c:if>

<c:if test="${!iscontain}">
<img id="sign_${device[0]}" name="sign_${device[0]}" 
src="images/expantion/add_sign.png"/>
</c:if>
</a>