struts1.x Series Tutorial (21): Using the Mappingdispatchaction class to invoke different action methods

Unlike Lookupdispatchaction and Dispatchaction, the Mappingdispatchaction class does not specify an action by requesting parameters, but instead corresponds a struts action to an action method. The following example shows how to use the Mappingdispatchaction class to match the struts action with the action method.

Implementation code for the Action class:

package　action;
import　org.apache.struts.actions.MappingDispatchAction;
……
public　class　MyMappingDispatchAction　extends　MappingDispatchAction
{
　　　 public　ActionForward　pdf(ActionMapping　mapping,　ActionForm　form,
　　　　　　　 HttpServletRequest　request,　HttpServletResponse　response) throws　IOException,　ServletException
　　　 {
　　 　　　　 //　　生成pdf文件
　　　 }
　　　 public　ActionForward　html(ActionMapping　mapping,　ActionForm　form,
　　　　　　　 HttpServletRequest　request,　HttpServletResponse　response) throws　IOException,　ServletException
　　　 {
　　　　　　　 //　　生成html文件
　　　 }
　　　 public　ActionForward　unspecified(ActionMapping　mapping,　ActionForm　form,
　　　　　　　 HttpServletRequest　request,　HttpServletResponse　response) throws　IOException,　ServletException
　　　 {
　　　　　　　 //　　处理默认动作
　　　 }
}

The above code has two action methods: PDF and HTML, which are used to generate PDFs and HTML files, respectively. There is also a unspecified method for handling default actions.

We can use the following code to configure the Mymappingdispatchaction class:

<action　path="/pdf"　type　=　"action.MyMappingDispatchAction"　parameter="pdf"　/>
<action　path="/html"　type　=　"action.MyMappingDispatchAction"　parameter="html"　/>

You can access PDFs and HTML actions by using the following URL, which calls the PDF and HTML methods of the Mymappingdispatchaction class, respectively:

Http://localhost:8080/samples/pdf.do

Http://localhost:8080/samples/html.do