org.apache.struts.actions

Class ActionDispatcher

Known Direct Subclasses:
EventActionDispatcher

public class ActionDispatcher
extends java.lang.Object

Action helper class that dispatches to a public method in an Action.

This class is provided as an alternative mechanism to using DispatchAction and its various flavours and means Dispatch behaviour can be easily implemented into any Action without having to inherit from a particular super Action.

To implement dispatch behaviour in an Action class, create your custom Action as follows, along with the methods you require (and optionally "cancelled" and "unspecified" methods):

   public class MyCustomAction extends Action {
 
       protected ActionDispatcher dispatcher
                = new ActionDispatcher(this, ActionDispatcher.MAPPING_FLAVOR);
 
       public ActionForward execute(ActionMapping mapping,
                                    ActionForm form,
                                    HttpServletRequest request,
                                    HttpServletResponse response)
                           throws Exception {
           return dispatcher.execute(mapping, form, request, response);
       }
   }
 

It provides three flavours of determing the name of the method:

Version:
$Revision: 383720 $ $Date: 2006-03-07 00:07:59 +0000 (Tue, 07 Mar 2006) $
Since:
Struts 1.2.7

Field Summary

static int
DEFAULT_FLAVOR
Indicates "default" dispatch flavor
static int
DISPATCH_FLAVOR
Indicates flavor compatible with DispatchAction
static int
MAPPING_FLAVOR
Indicates "mapping" dispatch flavor
protected Action
actionInstance
The associated Action to dispatch to.
protected Class
clazz
The Class instance of this DispatchAction class.
protected int
flavor
Indicates dispatch flavor
protected static Log
log
Commons Logging instance.
protected static MessageResources
messages
The message resources for this package.
protected HashMap
methods
The set of Method objects we have introspected for this class, keyed by method name.
protected Class[]
types
The set of argument type classes for the reflected method call.

Constructor Summary

ActionDispatcher(Action actionInstance)
ActionDispatcher(Action actionInstance, int flavor)

Method Summary

protected ActionForward
cancelled(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response)
Dispatches to the target class' cancelled method, if present, otherwise returns null.
protected ActionForward
dispatchMethod(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response, String name)
Dispatch to the specified method.
protected ActionForward
dispatchMethod(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response, String name, Method method)
Dispatch to the specified method.
ActionForward
execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response)
Process the specified HTTP request, and create the corresponding HTTP response (or forward to another web component that will create it).
protected Method
getMethod(String name)
Introspect the current class to identify a method of the specified name that accepts the same parameter types as the execute method does.
protected String
getMethodName(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response, String parameter)
Returns the method name, given a parameter's value.