Struts DispatchAction Example

The DispatchAction class (org.apache.struts.actions.DispatchAction) provides a way to group all related functions into a single action class. It’s a useful mechanism to avoid create separate action classe for each function.

To implement this mechanism, your action class need to extends org.apache.struts.actions.DispatchAction class, this action class does not need to implement the execute() method as normal action class does. Instead, the DispatchAction class will execute the method base on the incoming request parameter – method. For example, if the parameter is 「method=chinese」, then the chinese() method will be execute.

Example

A action class extends the DispatchAction, and contains four methods to set the locale into the Struts session attribute for the localization.

public class LanguageSelectAction extends DispatchAction{
    
    public ActionForward chinese(ActionMapping mapping,ActionForm form,
        HttpServletRequest request,HttpServletResponse response) 
    throws Exception {
        
        request.getSession().setAttribute(
                Globals.LOCALE_KEY, Locale.SIMPLIFIED_CHINESE);
        
        return mapping.findForward("success");
    }
    
    public ActionForward english(ActionMapping mapping,ActionForm form,
        HttpServletRequest request,HttpServletResponse response) 
    throws Exception {
        
        request.getSession().setAttribute(
                Globals.LOCALE_KEY, Locale.ENGLISH);
        
        return mapping.findForward("success");
    }
    
    public ActionForward german(ActionMapping mapping,ActionForm form,
        HttpServletRequest request,HttpServletResponse response) 
    throws Exception {
        
        request.getSession().setAttribute(
                Globals.LOCALE_KEY, Locale.GERMAN);
        
        return mapping.findForward("success");
    }
    
    public ActionForward france(ActionMapping mapping,ActionForm form,
        HttpServletRequest request,HttpServletResponse response) 
    throws Exception {
        
        request.getSession().setAttribute(
                Globals.LOCALE_KEY, Locale.FRANCE);
        
        return mapping.findForward("success");
    }
    
}

This Struts html tag will execute the chinese() method.

Chinese

This Struts html tag will execute the english() method.

English

This Struts html tag will execute the german() method.

German

This Struts html tag will execute the france() method.

France