org.apache.struts.actions
Class LookupDispatchAction

java.lang.Object
  |
  +--org.apache.struts.action.Action
        |
        +--org.apache.struts.actions.DispatchAction
              |
              +--org.apache.struts.actions.LookupDispatchAction

public abstract class LookupDispatchAction

extends DispatchAction

An abstract Action that dispatches to the subclass mapped execute method. This is useful in cases where an HTML form has multiple submit buttons with the same name. The button name is specified by the parameter property of the corresponding ActionMapping. To configure the use of this action in your struts-config.xml file, create an entry like this:

   <action path="/test"
           type="org.example.MyAction"
           name="MyForm"
          scope="request"
          input="/test.jsp"
      parameter="action"/>
 

which will use the value of the request parameter named "action" to locate the corresponding key in ApplicationResources. For example, you might have the following ApplicationResources.properties:

    button.add=Add Record
    button.delete=Delete Record
  

And your JSP would have the following format for submit buttons:

   <html:form action="/test">
    <html:submit property="action">
      <bean:message key="button.add"/>
    </html:submit>
    <html:submit property="action">
      <bean:message key="button.delete"/>
    </html:submit>
  </html:form>
  

Your subclass must implement both getKeyMethodMap and the methods defined in the map. An example of such implementations are:

  protected Map getKeyMethodMap() {
      Map map = new HashMap();
      map.put("button.add", "add");
      map.put("button.delete", "delete");
      return map;
  }

  public ActionForward add(ActionMapping mapping,
          ActionForm form,
          HttpServletRequest request,
          HttpServletResponse response)
          throws IOException, ServletException {
      // do add
      return mapping.findForward("success");
  }

  public ActionForward delete(ActionMapping mapping,
          ActionForm form,
          HttpServletRequest request,
          HttpServletResponse response)
          throws IOException, ServletException {
      // do delete
      return mapping.findForward("success");
  }
  


  Notes - If duplicate values exist for the keys returned by
  getKeys, only the first one found will be returned. If no corresponding key
  is found then an exception will be thrown.




Author:
  
Erik Hatcher, Scott Carlson, David Graham










Field Summary




protected  java.util.Map
keyMethodMap



          Resource key to method name lookup.



protected  java.util.Map
localeMap



          Reverse lookup map from resource value to resource key.


 
Fields inherited from class org.apache.struts.actions.DispatchAction
clazz, log, messages, methods, types
 
Fields inherited from class org.apache.struts.action.Action
ACTION_SERVLET_KEY, APPLICATION_KEY, DATA_SOURCE_KEY, defaultLocale, ERROR_KEY, EXCEPTION_KEY, FORM_BEANS_KEY, FORWARDS_KEY, LOCALE_KEY, MAPPING_KEY, MAPPINGS_KEY, MESSAGE_KEY, MESSAGES_KEY, MULTIPART_KEY, PLUG_INS_KEY, REQUEST_PROCESSOR_KEY, servlet, SERVLET_KEY, TRANSACTION_TOKEN_KEY
 



Constructor Summary
LookupDispatchAction()



           
 



Method Summary




 ActionForward
execute(ActionMapping mapping,
        ActionForm form,
        javax.servlet.http.HttpServletRequest request,
        javax.servlet.http.HttpServletResponse response)



          Process the specified HTTP request, and create the corresponding HTTP
  response (or forward to another web component that will create it).



protected abstract  java.util.Map
getKeyMethodMap()



          Provides the mapping from resource key to method name.


 
Methods inherited from class org.apache.struts.actions.DispatchAction
dispatchMethod, getMethod, unspecified
 
Methods inherited from class org.apache.struts.action.Action
execute, generateToken, getDataSource, getDataSource, getLocale, getResources, getResources, getResources, getServlet, isCancelled, isTokenValid, isTokenValid, perform, perform, resetToken, saveErrors, saveMessages, saveToken, setLocale, setServlet, toHex
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 





Field Detail



localeMap
protected java.util.Map localeMap

Reverse lookup map from resource value to resource key.







keyMethodMap
protected java.util.Map keyMethodMap

Resource key to method name lookup.








Constructor Detail



LookupDispatchAction
public LookupDispatchAction()






Method Detail



execute
public ActionForward execute(ActionMapping mapping,
                             ActionForm form,
                             javax.servlet.http.HttpServletRequest request,
                             javax.servlet.http.HttpServletResponse response)
                      throws java.lang.Exception

Process the specified HTTP request, and create the corresponding HTTP
  response (or forward to another web component that will create it).
  Return an ActionForward instance describing where and how
  control should be forwarded, or null if the response has
  already been completed.


Overrides:
execute in class DispatchAction


Parameters:
mapping - The ActionMapping used to select this instance
request - The HTTP request we are processing
response - The HTTP response we are creating
form - The optional ActionForm bean for this request (if any)
Returns:
Describes where and how control should be forwarded.
Throws:
java.lang.Exception - if an error occurs





getKeyMethodMap
protected abstract java.util.Map getKeyMethodMap()

Provides the mapping from resource key to method name.



Returns:
Resource key / method name map.