在jsp页面用到jstl的if或when标签判断字符串不为空的时候,书写格式:
<c:when test="${not empty paramName}">
</c:when>
<c:when test="${paramName != ''}">
</c:when>
在jsp页面用到jstl的if或when标签判断字符串为空的时候,书写格式:
<c:when test="${empty paramName}">
</c:when>
<c:when test="${paramName == null or paramName == ''}">
</c:when>