<s:select> with optgroup in Struts2

Question

I am working on a task of migrating existing Struts1 application to Struts2. I am stuck in the problem. Within an <s:select> I need to categories the options with <optgroup>. The following code would do this in Struts1. How can I achieve this with Struts2?

<html:select id="foodList" property="foodItemId" onclick="selectRadio('0')">
    <c:if test="${not empty foodList1}">
        <optgroup label="Risk Analysis Report Sets">
            <c:forEach var="item" items="${foodList1}">
                <option value="${item.value}">${item.label}</option>
            </c:forEach>
        </optgroup>
    </c:if>
    <c:if test="${not empty foodList2}">
        <optgroup label="NMX Report Sets">
    <c:forEach var="item" items="${foodList2}">
                <option value="${item.value}">${item.label}</option>
            </c:forEach>
        </optgroup>
    </c:if>
    <c:if test="${not empty foodList3}">
        <optgroup label="Standard Report Sets">
            <c:forEach var="item" items="${list3}">
                <option value="${item.value}">${item.label}</option>
            </c:forEach>
        </optgroup>
    </c:if>
</html:select>

Answer 1

<s:optgroup/> is your friend here.

From Struts2 JavaDoc:

org.apache.struts2.components

Class OptGroup

Create a optgroup component which needs to resides within a select tag.

This component is to be used within a Select component.

<s:select label = "My Selection"
           name = "mySelection"
          value = "%{'POPEYE'}"
           list = "%{#{'SUPERMAN':'Superman', 'SPIDERMAN':'spiderman'}}">

    <s:optgroup label = "Adult"
                 list = "%{#{'SOUTH_PARK':'South Park'}}" />
    <s:optgroup label = "Japanese"
                 list = "%{#{'POKEMON':'pokemon','DIGIMON':'digimon'}}" />
</s:select>