Jakarta Struts Cookbook

5.1. Creating Dynamic Action Forms

Problem

You want to create ActionForms for use on your pages without having to handcode a unique Java class for each form.

Solution

Create a form-bean in the struts-config.xml file using the built-in DynaActionForm type or any of its subclasses. Then define the properties of the form using nested form-property elements:

<form-beans>
  <form-bean name="MyForm" type="org.apache.struts.action.DynaActionForm">
    <form-property name="foo" type="java.lang.String"/>
    <form-property name="bar" type="java.lang.String"/>
    <form-property name="baz" type="java.lang.Boolean"/>
    <form-property name="blindMice" type="java.lang.String[]"
                   size="3"/>
  </form-bean>
<form-beans>

You can retrieve the data from the form using methods of the DynaActionForm or generically using the Jakarta Commons PropertyUtils class. The Action shown in Example 5-1 uses this technique to get the form property values by name.

Example 5-1. Using PropertyUtils with ActionForms

package com.oreilly.strutsckbk.ch05; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.beanutils.PropertyUtils; import org.apache.struts.action.Action; import org.apache.struts.action.ActionForm; import org.apache.struts.action.ActionForward; import org.apache.struts.action.ActionMapping; public class ProcessAction extends Action { public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws ...