Struts2 increment a previous set <s:set /> value

Question

I'm working on JSPs with Struts2, I have to iterate on two lists, and change the background code of each <tr/> printed.

My JSP snippet:

<s:set var="counter" value="0" scope="page" />
<s:iterator value="listaContoCapitale" status="i">
    <s:iterator value="utilizzi" status="j">

    <s:if test="#counter == 0 || #counter % 2 == 0">
        <s:set var="trclass" value="'rigaSfondo1'" scope="page" />
    </s:if>
    <s:else>
        <s:set var="trclass" value="''" scope="page" />
    </s:else> 
    <tr class="${trclass}">
        ....tds
    </tr>
    </s:iterator>
    <s:set var="counter" value="here i have to change its value (increment it by1)" />
</s:iterator>

I need to increment my counter every step on the inner loop. Is there a way to increment my counter value by a simple struts tag? I know I could use Java scriptlet but I rather keep the JSP clear if possible.

Arthritis

In addition to Roman's answer, consider using a ternary to shorten the class decision logic – Flori

What do you mean with ternary? – Arthritis

Answer 1

You aren't required to create a reference variable just use #i.index or #i.count inside the iterator. It's already incremented by the iterator tag itself.

Note that "count" is 1-based, "index" is 0-based.

Always check the docs.

If you still need your own counter

<s:set var="counter" value="0"/>

increment

<s:set var="counter" value="%{#counter+1}"/>

Artificial

Need a separate counter because it needs to be based on the inner loop and not reset when the outer loop bumps up. – Flori

I can't use the basic counter of an iterator, if you check my code you'll see that neither the outer loop nor the inner loop would give me a right counter that alternates from odd to even, in order to set the background color (trclass variable); in any case it doesn't matter if it starts with 0 or 1.... Before posting my question i tried your solution (<s:set var="counter" value="%{#counter+1}"/>) but it gave me an error by translating the JSP page. Tomorrow i'll try it again... – Arthritis

to check that odd or even you could use j.even or j.odd it's boolean values. The last statement should work, isn't it? – Artificial

Works like a charm, use <s:property value="#counter"/> to display it. – Artificial

<s:set var="counter" value="%{#counter+1}"/> works, but only if i remove the scope from de first definition. – Arthritis

@dom this question is dated more than 3 years ago. if you have a question and after deep search on SO you didn't find the answer, you can as a question. – Artificial

Answer 2

You Can Use this easy Way to Do this struts2 increment

<s:set var="count" value="1"/>
<s:iterator value="yourlisthere">
<div><s:property value="#count" /><s:property/></div>
<s:set var="counter" value="%{#count+1}"/>
<s:set var="count" value="%{#counter}"/>
</s:iterator>

jsp struts2

Coarsen