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     lt    taglib prefix  c  uri  http   java sun com jsp jstl core    gt   lt    taglib prefix  fn  uri  http   java sun com jsp jstl functions    gt     lt c if test    fn length attachments   gt  0   gt       lt c forEach var  attachment  items    attachments   varStatus  loopCount  gt           lt c if test    loopCount count eq 1   gt           attachment id          lt  c if gt       lt  c forEach gt   lt  c if gt

User · Answer

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

User · Answer

You can access individual elements with the array    operator    lt c out value    attachments 0  id     gt    This will work for arrays and lists  It won t work for maps and sets  In that case you must put the key of the element inside the brackets

User · Answer

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    lt c choose gt       lt c when test    dealership administeredBy size      1   gt          Hello   dealership administeredBy iterator   next   firstName   lt br  gt       lt  c when gt       lt c when test    dealership administeredBy size    gt  1   gt          Hello Administrators  lt br  gt       lt  c when gt       lt c otherwise gt       lt  c otherwise gt   lt  c choose gt

User · Answer

You can use the EL 3 0 Stream API    lt div gt   attachments stream   findFirst   get    lt  div gt    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

User · Answer

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                        lt ul gt                           lt c forEach items    actionBean top25Teams   begin  0  end  8  var  team  varStatus  counter  gt                               lt li gt   team name  lt  li gt                                                          lt  c forEach gt                        lt  ul gt                        lt ul gt                           lt c forEach items    actionBean top25Teams   begin  9  end  17  var  team  varStatus  counter  gt                               lt li gt   team name  lt  li gt                                                          lt  c forEach gt                        lt  ul gt                        lt ul gt                           lt c forEach items    actionBean top25Teams   begin  18  end  25  var  team  varStatus  counter  gt                               lt li gt   team name  lt  li gt                                                          lt  c forEach gt                        lt  ul gt

User · Answer

Work for arrays and lists only  not for set

User · Answer

Since i have have just one element in my Set the order is not important So I can access to the first element like this       attachments iterator   next   id

User · Answer

Sets have no order  but if you still want to get the first element you can use the following    lt c forEach var  attachment  items    attachments   end  0  gt        lt c out value    attachment id    gt   lt  c forEach gt

User · Answer

Using   mySet toArray 0   does not work   I do not think it is possible without having forEach loop at least one iteration

[jakarta-ee] How to select the first element of a set with JSTL?

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