Struts - How not to lose parameter after validate() method

Question

Hi
I have following problem. When I submit a form(action= sendMessage.do) from site generated in writeMessage.do?id=1 action and validate method find errors it forwards to writeMessage.do I need to forward to writeMessage.do?id=1
<action path="/sendMessage"
type="SendMessageAction"
name="writeMessageForm"
scope="request"
validate="true"
input="/writeMessage.do">
<forward name="ok" path="/info.jsp"/>
</action>
I need something like input="/writeMessage.do?id=xx" , but xx will be changing in runtime. How to solve that problem?

Answer 1

Swap input="/writeMessage.do" with input="/sendMessage.jsp" (or whatever the name of the input JSP was). If I remember rightly this will fix it for the automatic validation errors, however you'll still get this problem if you need to test business rules/custom validation rules from within your application. To fix this copy the following class and specify a className attribute for your action element in the struts config
i.e. <action ... className="com.whatever.CustomActionMapping" ... />
package com.whatever
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
public class CustomActionMapping extends ActionMapping
    public ActionForward findForward(String forwardName, HashMap requestParams)
        ActionForward fwd = findForward(forwardName);
        Iterator iter1 = requestParams.keySet().iterator();       
        if (iter1.hasNext())
            StringBuffer basePath = new StringBuffer(fwd.getPath());           
            basePath.append("?");
             while (iter1.hasNext())
                 String paramName = (String) iter1.next();
                 ArrayList paramValues = (ArrayList) requestParams.get(paramName);
                 Iterator iter2 = paramValues.iterator();
                 while (iter2.hasNext())
                     String paramValue = String.valueOf(iter2.next());
                      basePath.append(paramName);
                      basePath.append("=");
                      basePath.append(paramValue);
                      if (iter2.hasNext())
                          basePath.append("&");
                 if (iter1.hasNext())
                     basePath.append("&");
             fwd = new ActionForward(fwd);
             fwd.setPath(basePath.toString());
        return fwd;
}Then in the execute method of your action do something like
// Creates a map to store the request parameters in
HashMap requestParams = new HashMap();
// Helper method to extract a request parameter for 'teamId'
Integer teamId = RequestHelper.getTeamIdParam(request);       
// Adds the teamId parameter to the hash map
setRequestParam(RequestHelper.TEAM_ID, teamId, requestParams);
// Creates a new forward with the required request parameters dynamically appended to the forward path
return ((CustomActionMapping) mapping).findForward(forwardName, requestParams);