org.apache.struts.actions
Class DispatchAction
public abstract class DispatchAction
An abstract
Action that dispatches to a public
method that is named by the request parameter whose name is specified
by the
parameter
property of the corresponding
ActionMapping. This Action is useful for developers who prefer to
combine many similar actions into a single Action class, in order to
simplify their application design.
To configure the use of this action in your
struts-config.xml
file, create an entry like this:
<action path="/saveSubscription"
type="org.apache.struts.actions.DispatchAction"
name="subscriptionForm"
scope="request"
input="/subscription.jsp"
parameter="method"/>
which will use the value of the request parameter named "method"
to pick the appropriate "execute" method, which must have the same
signature (other than method name) of the standard Action.execute
method. For example, you might have the following three methods in the
same action:
- public ActionForward delete(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception
- public ActionForward insert(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception
- public ActionForward update(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception
and call one of the methods with a URL like this:
http://localhost:8080/myapp/saveSubscription.do?method=update
NOTE - All of the other mapping characteristics of
this action must be shared by the various handlers. This places some
constraints over what types of handlers may reasonably be packaged into
the same
DispatchAction
subclass.
Version:
- Niall Pemberton
- Craig R. McClanahan
- Ted Husted
protected Class | clazz - The Class instance of this
DispatchAction class.
|
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.
|
ACTION_SERVLET_KEY , APPLICATION_KEY , DATA_SOURCE_KEY , ERROR_KEY , EXCEPTION_KEY , FORM_BEANS_KEY , FORWARDS_KEY , LOCALE_KEY , MAPPINGS_KEY , MAPPING_KEY , MESSAGES_KEY , MESSAGE_KEY , MULTIPART_KEY , PLUG_INS_KEY , REQUEST_PROCESSOR_KEY , SERVLET_KEY , TRANSACTION_TOKEN_KEY , defaultLocale , servlet , token |
protected ActionForward | dispatchMethod(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response, String name) - 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 ActionForward | unspecified(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) - Method which is dispatched to when there is no value for specified
request parameter included in the request.
|
execute , execute , generateToken , getDataSource , getDataSource , getLocale , getResources , getResources , getResources , getServlet , isCancelled , isTokenValid , isTokenValid , perform , perform , resetToken , saveErrors , saveMessages , saveToken , setLocale , setServlet , toHex |
clazz
protected Class clazz
The Class instance of this DispatchAction
class.
log
protected static Log log
Commons Logging instance.
messages
protected static MessageResources messages
The message resources for this package.
methods
protected HashMap methods
The set of Method objects we have introspected for this class,
keyed by method name. This collection is populated as different
methods are called, so that introspection needs to occur only
once per method name.
types
protected Class[] types
The set of argument type classes for the reflected method call. These
are the same for all calls, so calculate them only once.
dispatchMethod
protected ActionForward dispatchMethod(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response,
String name)
throws Exception
Dispatch to the specified method.
- Struts 1.1
execute
public ActionForward execute(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws 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.
- execute in interface Action
mapping
- The ActionMapping used to select this instanceform
- The optional ActionForm bean for this request (if any)request
- The HTTP request we are processingresponse
- The HTTP response we are creating
getMethod
protected Method getMethod(String name)
throws NoSuchMethodException
Introspect the current class to identify a method of the specified
name that accepts the same parameter types as the execute
method does.
name
- Name of the method to be introspected
unspecified
protected ActionForward unspecified(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception
Method which is dispatched to when there is no value for specified
request parameter included in the request. Subclasses of
DispatchAction
should override this method if they wish
to provide default behavior different than producing an HTTP
"Bad Request" error.
Copyright B) 2000-2005 - Apache Software Foundation