How to get index of selected item of jsf f:selectItems?

Question

I have seleconeradio, for example:

<h:selectOneRadio value="#{myBean.selectedValue}" layout="pageDirection">
    <f:selectItems value="#{myBean.myList}" var="a" itemValue="#{a}" itemLabel="#{a}"/>
</h:selectOneRadio>

where myList is list of integers, e.g. 1,3,2,4. If user selects second element (i.e. 3) I want in myBean selectedValue to be 2, so I want to get index of selectItems item.

What should I write in f:selectItems itemValue tag? Or it is impossible?

P.S. I can do it by creating a new class in which I have the index property and create a new list of that class, giving the right index. But it is very bad solution.

Answer 1

you should use indexOf(Object o) .. it returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element... your code should probably look like this..

int index  = myList.indexof(selectedValue);

Answer 2

You can actually use c:forEach for this case. This is especially usefull when you have to deal with a collection containing duplicates and therefore can't use indexOf() for example.

<h:selectOneRadio value="#{myBean.selectedValue}" layout="pageDirection">
  <c:forEach items="#{myBean.myList}" var="a" varStatus="idx">
    <f:selectItem itemValue="#{idx.index}" itemLabel="#{a}"/>
  </c:forEach>
</h:selectOneRadio>

Just be sure to include the JSP JSTL Core namespace if you haven't done yet.

xmlns:c="http://xmlns.jcp.org/jsp/jstl/core