org.beyondcode.struts.dispatcher
Class FormDispatcherAction

java.lang.Object
  |
  +--org.apache.struts.action.Action
        |
        +--org.beyondcode.struts.dispatcher.FormDispatcherAction

public class FormDispatcherAction

extends org.apache.struts.action.Action

This class forwards an incoming request to another Action, when it finds a request parameter with the same name as one the local forwards.

In Struts, an HTML form is always submitted to a single action. In case the HTML form has several submit button, this class can be used to select which one has been clicked and forward the request to a different action accordingly.

Example: JSP:

  ...
  <html:form action="/formHandler">
    ...
    <html:submit property="delete" value="Delete Selected" />
    <html:submit property="save" value="Save Selected" />
  </html:form>
  ...
  

struts-config.xml:

  ...
  <action path="/formHandler" type="org.beyondcode.struts.dispatcher.FormDispatcherAction">
    <forward name="delete" path="/demo/delete" redirect="false" />
    <forward name="save" path="/demo/save" redirect="false" />
  </action>
          
  <action path="/delete" type="HomeAction" >
    <set-property property="method" value="doDelete" />
    <forward name="success" path="/WEB-INF/jsp/page.jsp" redirect="false" />
  </action>
 
  <action path="/save" type="HomeAction" >
    <set-property property="method" value="doSave" />
    <forward name="success" path="/WEB-INF/jsp/page.jsp" redirect="false" />
  </action>
  ...
  

This class does not need to be extended for custom applications!

Author:

Philipp K. Janert

Field Summary

protected static org.apache.struts.util.MessageResources

messages Handle to properties file with error messages.

Fields inherited from class org.apache.struts.action.Action

DATA_SOURCE_KEY, defaultLocale, ERROR_KEY, EXCEPTION_KEY, FORM_BEANS_KEY, FORWARDS_KEY, LOCALE_KEY, MAPPING_KEY, MAPPINGS_KEY, MESSAGES_KEY, MULTIPART_KEY, servlet, SERVLET_KEY, TRANSACTION_TOKEN_KEY

Constructor Summary

FormDispatcherAction()

Method Summary

org.apache.struts.action.ActionForward

perform(org.apache.struts.action.ActionMapping mapping, org.apache.struts.action.ActionForm form, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) This method compares the names of the request parameters and the names of the ActionForwards (as defined in the mapping).

Methods inherited from class org.apache.struts.action.Action

generateToken, getLocale, getResources, getServlet, isCancelled, isTokenValid, perform, perform, perform, resetToken, saveErrors, saveToken, setLocale, setServlet, toHex

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

messages

protected static org.apache.struts.util.MessageResources messages

Handle to properties file with error messages.

Constructor Detail

FormDispatcherAction

public FormDispatcherAction()

Method Detail

perform

public org.apache.struts.action.ActionForward perform(org.apache.struts.action.ActionMapping mapping,
                                                      org.apache.struts.action.ActionForm form,
                                                      javax.servlet.http.HttpServletRequest request,
                                                      javax.servlet.http.HttpServletResponse response)

This method compares the names of the request parameters and the names of the ActionForwards (as defined in the mapping). When it finds a request parameter with the same name as one of the forwards, it transfers control to the Action given by the Path property of the respective forward. The transfer is done as a local dispatch (not through client redirection). If no match is found, null is returned. If several matches exist, one is chosen arbitrarily.

Overrides:

perform in class org.apache.struts.action.Action

Parameters:

mapping -

form -

request -

response -

Returns:

Selected forward, or null if none found.