How to compare parameters in JSTL

Question

I have list of ID's from a database and pass them in a request to a servlet, but i can't compare them to any number.

I think maybe i have to convert them to integer type:

    <c:forEach items="${subjec.id}" var="x">
${x}
  </c:forEach>
<c:forEach items="${listPage}" var = "list">
${list.id} 
<c:choose>
<c:when test="${list.id} == 1">

</c:when>
</c:choose>

</c:forEach>
<c:if test="${subject1.id == 1}"> 
${subject1.id}
</c:if>

However, I cant test based on Integer format. Any suggetions for this case?

Solution 1

<c:when test="${list.id} == 1">

This is wrong. You need to put the entire expression inside ${}.

If getId() returns a Number (integer, long, etc), then use the following:

<c:when test="${list.id == 1}">

Or if it returns a String (which is unnatural by the way), then use the following:

<c:when test="${list.id == '1'}">

Or if it returns a boolean (just as an example), then use the following:

<c:when test="${list.id}">

Solution 2

it should be <c:when test="${list.id == '1'}">
if you use <c:when test='${list.id == "1"}'> exception will be thrown