org.apache.struts.actions
public class MappingDispatchAction extends DispatchAction
An abstract Action that dispatches to a public
method that is named by the parameter
attribute of
the corresponding ActionMapping. This is useful for developers who prefer
to combine many related actions into a single Action class.
To configure the use of this action in your
struts-config.xml
file, create an entry like this:
<action path="/saveSubscription"
type="org.example.SubscriptionAction"
name="subscriptionForm"
scope="request"
input="/subscription.jsp"
parameter="method"/>
where 'method' is the name of a method in your subclass of MappingDispatchAction that has the same signature (other than method name) of the standard Action.execute method. For example, you might combine the methods for managing a subscription into a single MappingDispatchAction class using the following methods:
for which you would create corresponding <action> configurations that reference this class:
<action path="/createSubscription"
type="org.example.SubscriptionAction"
parameter="create">
<forward name="success" path="/editSubscription.jsp"/>
</action>
<action path="/editSubscription"
type="org.example.SubscriptionAction"
parameter="edit">
<forward name="success" path="/editSubscription.jsp"/>
</action>
<action path="/saveSubscription"
type="org.example.SubscriptionAction"
parameter="save"
name="subscriptionForm"
validate="true"
input="/editSubscription.jsp"
scope="request">
<forward name="success" path="/savedSubscription.jsp"/>
</action>
<action path="/deleteSubscription"
type="org.example.SubscriptionAction"
name="subscriptionForm"
scope="request"
input="/subscription.jsp"
parameter="delete">
<forward name="success" path="/deletedSubscription.jsp"/>
</action>
<action path="/listSubscriptions"
type="org.example.SubscriptionAction"
parameter="list">
<forward name="success" path="/subscriptionList.jsp"/>
</action>
NOTE - Unlike DispatchAction, mapping characteristics may differ between the various handlers, so you can combine actions in the same class that, for example, differ in their use of forms or validation. Also, a request parameter, which would be visible to the application user, is not required to enable selection of the handler method.
Since: Struts 1.2
Version: $Rev: 54929 $ $Date: 2004-10-16 17:38:42 +0100 (Sat, 16 Oct 2004) $
Field Summary | |
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static Log | log
Commons Logging instance. |
Method Summary | |
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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 String | getMethodName(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response, String parameter)
Returns the method name, given a parameter's value.
|
protected ActionForward | unspecified(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response)
Method which is dispatched to when there is no value for the
parameter in the ActionMapping. |
ActionForward
instance describing where and how
control should be forwarded, or null
if the response has
already been completed.
This method dispatches the request to other methods of
MappingDispatchAction
using the 'parameter' attribute of
ActionMapping
and Java Introspection.
Parameters: mapping The ActionMapping used to select this instance form The optional ActionForm bean for this request (if any) request The HTTP request we are processing response The HTTP response we are creating
Returns: Return an ActionForward
instance describing where
and how control should be forwarded, or null
if
the response has already been completed.
Throws: Exception if an exception occurs
Parameters: mapping The ActionMapping used to select this instance form The optional ActionForm bean for this request (if any) request The HTTP request we are processing response The HTTP response we are creating parameter The ActionMapping
parameter's name
Returns: The method's name.
Since: Struts 1.2.0
MappingDispatchAction
should override this method
if they wish to provide default behavior different than throwing a
ServletException.
Parameters: mapping The ActionMapping used to select this instance form The optional ActionForm bean for this request (if any) request The HTTP request we are processing response The HTTP response we are creating
Returns: Return an ActionForward
instance describing where
and how control should be forwarded, or null
if
the response has already been completed.
Throws: Exception if an exception occurs