How to select the first element of a set with JSTL?

Question

I managed to do it with the next code but there must be an easier way.

<%@ taglib prefix=\"c\" uri=\"http://java.sun.com/jsp/jstl/core\" %>
<%@ tag         


        

Answer 1

Using begin and end seemed to work for me to select a range of elements. This gives me three separate lists. The first list with items 1-9, second list with items 10-18, and the last list with items 11-25.

                    <ul>
                        <c:forEach items="${actionBean.top25Teams}" begin="0" end="8" var="team" varStatus="counter">
                            <li>${team.name}</li>                               
                        </c:forEach> 
                    </ul>

                    <ul>
                        <c:forEach items="${actionBean.top25Teams}" begin="9" end="17" var="team" varStatus="counter">
                            <li>${team.name}</li>                               
                        </c:forEach> 
                    </ul>

                    <ul>
                        <c:forEach items="${actionBean.top25Teams}" begin="18" end="25" var="team" varStatus="counter">
                            <li>${team.name}</li>                               
                        </c:forEach> 
                    </ul>

Answer 2

If you only want the first element of a set (and you are certain there is at least one element) you can do the following:

<c:choose>
    <c:when test="${dealership.administeredBy.size() == 1}">
        Hello ${dealership.administeredBy.iterator().next().firstName},<br/>
    </c:when>
    <c:when test="${dealership.administeredBy.size() > 1}">
        Hello Administrators,<br/>
    </c:when>
    <c:otherwise>
    </c:otherwise>
</c:choose>

Answer 3

Work for arrays and lists only, not for set.

Answer 4

You can use the EL 3.0 Stream API.

<div>${attachments.stream().findFirst().get()}</div>

Be careful! The EL 3.0 Stream API was finalized before the Java 8 Stream API and it is different than that. They can't sunc both apis because it will break the backward compatibility.

Answer 5

Sets have no order, but if you still want to get the first element you can use the following:

<c:forEach var="attachment" items="${attachments}" end="0">
     <c:out value="${attachment.id} />
</c:forEach>

Answer 6

Look here for a description of the statusVar variable. You can do something like below, where the "status" variable contains the current status of the iteration. This is very useful if you need special annotations for the first and last iteraton. In the case below I want to ommit the comma behind the last tag. Of course you can replace status.last with status.first to do something special on the first itteration:

<td>
    <c:forEach var="tag" items="${idea.tags}" varStatus="status">
        <span>${tag.name not status.last ? ', ' : ''}</span>
    </c:forEach>
</td>

Possible options are: current, index, count, first, last, begin, step, and end