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="method"/>

which will use the value of the request parameter named "method" 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="method">

<bean:message key="button.add"/>

</html:submit>

<html:submit property="method">

<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. You can override the

method unspecified to provide a custom handler. If the submit

was cancelled (a html:cancel button was pressed), the custom

handler cancelled will be used instead.

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

defaultLocale, servlet

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.

protected java.lang.String

getLookupMapName(javax.servlet.http.HttpServletRequest request, java.lang.String keyName, ActionMapping mapping)

Lookup the method name corresponding to the client request's locale.

protected java.lang.String

getMethodName(ActionMapping mapping, ActionForm form, javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, java.lang.String parameter)

Returns the method name, given a parameter's value.

private java.util.Map

initLookupMap(javax.servlet.http.HttpServletRequest request, java.util.Locale userLocale)

This is the first time this Locale is used so build the reverse lookup Map.

Methods inherited from class org.apache.struts.actions.DispatchAction

cancelled, dispatchMethod, getMethod, unspecified

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

addErrors, addMessages, execute, generateToken, getDataSource, getDataSource, getErrors, getLocale, getMessages, getResources, getResources, getServlet, isCancelled, isTokenValid, isTokenValid, resetToken, saveErrors, saveErrors, saveMessages, saveMessages, saveToken, setLocale, setServlet

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 instancerequest - The HTTP request we are processingresponse - The HTTP response we are creatingform - 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

initLookupMap

private java.util.Map initLookupMap(javax.servlet.http.HttpServletRequest request,

java.util.Locale userLocale)

This is the first time this Locale is used so build the reverse lookup Map.

Search for message keys in all configured MessageResources for

the current module.

getKeyMethodMap

protected abstract java.util.Map getKeyMethodMap()

Provides the mapping from resource key to method name.

Returns:Resource key / method name map.

getLookupMapName

protected java.lang.String getLookupMapName(javax.servlet.http.HttpServletRequest request,

java.lang.String keyName,

ActionMapping mapping)

throws javax.servlet.ServletException

Lookup the method name corresponding to the client request's locale.

Parameters:request - The HTTP request we are processingkeyName - The parameter name to use as the properties keymapping - The ActionMapping used to select this instance

Returns:The method's localized name.

Throws:

javax.servlet.ServletException - if keyName cannot be resolvedSince:

Struts 1.2.0

getMethodName

protected java.lang.String getMethodName(ActionMapping mapping,

ActionForm form,

javax.servlet.http.HttpServletRequest request,

javax.servlet.http.HttpServletResponse response,

java.lang.String parameter)

throws java.lang.Exception

Returns the method name, given a parameter's value.

Overrides:getMethodName in class DispatchAction

Parameters: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 creatingparameter - The ActionMapping parameter's name

Returns:The method's name.

Throws:

java.lang.ExceptionSince:

Struts 1.2.0

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