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Editorial Team
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Asked: 2026-06-06T21:33:18+00:00

I’ve been researching this for a while. I’ve read How to update a the

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I’ve been researching this for a while. I’ve read
How to update a the contents of a list displayed on JSP using Struts2?
and it is very close to what I need, but I’m still not quite able to get my problem resolved.

I have a java.util.Set of objects. The class is ‘Event’, and the name of the set is ‘events’. I want to present a form in a JSP that allows the user to modify attributes of the Event objects, but I want to update more than one at a time. Here is my JSP snippet :

<s:form theme="simple">
  <table>
    <s:iterator value="events" var="ev">
    <tr>
      <td> <s:textfield name="?????" value="%{#ev.price}" </td>
      <td> <s:textfield name="?????" value="%{#ev.amount}" </td>
     </tr>
     </s:iterator>
     <tr><td colspan="2">
       <s:submit value="Apply" action="EditEventsAction_save" ></s:submit>
     </td></tr>
  </table>
</s:form>

My problem is (I think) what needs to go in the name of the texfield in order to update my Set.

How can I specify that the data in the textfield is supposed to update a member of my Set?

Is this possible?

UPDATE

This is my latest (simplified) attempt, based largely on what I read in the type conversion docs.

The form is populated correctly, but changes entered in the textfield are not captured on submit.

Action class:

public class TestAction extends ActionSupport implements Preparable {

    private static HashMap<Integer, AssetId> assetMap = new HashMap<Integer, AssetId>();

    public String execute () {
        return SUCCESS;
    }   

    public void prepare() throws Exception {
        AssetId a1 = new AssetId(1, "Asset 1");
        AssetId a2 = new AssetId(2, "Asset 2");
        AssetId a3 = new AssetId(3, "Asset 3");
        assetMap.put(1, a1);
        assetMap.put(2, a2);
        assetMap.put(3, a3);
    }

    public String save () {
        return SUCCESS;
    }

    public static HashMap<Integer, AssetId> getAssetMap() {
        return assetMap;
    }

    public static void setAssetMap(HashMap<Integer, AssetId> assetMap) {
        TestAction.assetMap = assetMap;
    }
}

JSP:

<%@ taglib uri="/struts-tags" prefix="s" %>

<html>
  <body>      
    <s:form theme="simple">
      <table>
        <s:iterator value="assetMap" var="asset">
          <tr>
            <td><s:textfield name="assetMap[key].clientId"  /></td>
          </tr>
        </s:iterator>
        <tr><td colspan="2"><s:submit value="Apply!" action="TestAction_save" /></td></tr>
      </table>
    </s:form>
  </body>
</html>

AssetId class:

public class AssetId implements java.io.Serializable {
    private int assetId;
    private String clientId;
    // And public getters/setters
}

TestAction-conversion.properties

Key_assetMap=java.lang.Integer
Element_assetMap=AssetId
CreateIfNull_assetMap=false
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1 Answer

  1. Editorial Team

    There are a number of issues; you should have seen stack traces in your log file.

    Most important: you didn’t check the rendered HTML. If you had, you’d have seen key rendering as-is–unevaluated. My fault (comment was incomplete), although the docs show the OGNL escape.

    <s:textfield name="assetMap[%{key}].clientId" />

    Since you’re trying to evaluate the key of the current object of iteration you must wrap it in the OGNL escape sequence–you don’t want to evaluate the rest. This renders:

    <input type="text" name="assetMap[1].clientId" value="foo" id="map_save_assetMap_1__clientId"/>

    Always check the rendered HTML.

    Eventually the static map will be an issue. It should be an instance property (or, I suppose, a ThreadLocal, but IMO you’d struggle to justify that).

    You should not need the type conversion file at this point; that’s largely a legacy artifact. You should have seen an exception about not being able to find the AssetId class, too.

    Once those things are taken care of if I log the asset map in my submit method, I see:

    {1=foo.AssetId@502c06b2, 2=foo.AssetId@7a6bb93c, 3=foo.AssetId@364e50ee}
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