与根源javax.el.E​​LException：

Question

我在jsp页面下面的代码

<a href="javascript:void(0)" style="<c:if test="${fn:length(page.likes)}">display:none</c:if>" class="like">Like</a>&nbsp; 

我收到以下异常

javax.el.ELException: Cannot convert 1 of type class java.lang.Integer to class java.lang.Boolean 
org.apache.el.lang.ELSupport.coerceToBoolean(ELSupport.java:207) 
org.apache.el.lang.ELSupport.coerceToType(ELSupport.java:402) 

Answer 1

答案是

<c:if test="${(fn:length(page.likes))==0}"> :)