JSF和struts基于框架的错误控制与封装处理

在struts中，通常采用的全局错误控制模式是构建一个baseAction，在其execute方法中完成前台传回方法的dispatch操作，并由 try...catch...捕获程序错误，实现错误的控制和展示。一个典型的BaseAction例子如下：

public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) {
                ......

                ActionForward forwardPage = null;

                try {
                        String parameter = mapping.getParameter();

                        if (parameter == null) {
                                String message = messages.getMessage("dispatch.handler", mapping.getPath());
                                response.sendError(500, message);
                                return null;
                        }

                        String name = processReqCode(request.getParameter(parameter));

                        forwardPage = dispatchMethod(mapping, form, request, response, name);
                } catch (BaseException ex) {
                        if (log.isDebugEnabled())
                                log.debug("发生错误:", ex);

                        forwardPage = processBaseException(request, mapping, ex);
                } catch (Throwable ex) {
                        log.error("发生错误:", ex);

                        ActionMessages errors = new ActionMessages();

                        ByteArrayOutputStream ostr = new ByteArrayOutputStream();
                        ex.printStackTrace(new PrintStream(ostr));
                        errors.add("org.apache.struts.action.GLOBAL_MESSAGE", new ActionMessage(ostr.toString()));

                        saveErrors(request, errors);
                        forwardPage = mapping.findForward("syserror");
                        output.setStatus("fail");
                        output.setError(ex.getMessage());
                }
                
                ......
}

由于JSF采用了managed bean，JSP页面直接通过调用managed bean中的方法完成数据交互，不能像struts一样通过捕获dispatch操作过程抛出的异常来完成错误的处理(因为根本就没有dispatch方法)，似乎jsf根本就不支持全局的错误处理。
如果在managed bean中throw 一个exception(这里是AppException)，观察一下控制台的日志，可以看到其实错误是从一个ActionListener的实现中抛出的(针对myfaces，这里是ActionListenerImpl)，参考jsf的生命周期过程，方法出来了：

public class GlobalActionListener extends ActionListenerImpl {

        public void processAction(ActionEvent event) throws AbortProcessingException {
                FacesContext facesContext = FacesContext.getCurrentInstance();
                Application application = facesContext.getApplication();

                ActionSource actionSource = (ActionSource) event.getComponent();
                MethodBinding methodBinding = actionSource.getAction();

                String fromAction = null;
                String outcome = null;
                if (methodBinding != null) {
                        fromAction = methodBinding.getExpressionString();

                        try {
                                outcome = (String) methodBinding.invoke(facesContext, null);
                        } catch (EvaluationException e) {
                                Throwable cause = e.getCause();
                                
                                if (cause != null && cause instanceof AppException) {
                                //这里需要根据框架的不同，判断实例是否是程序中手动抛出的错误        FacesUtils.addErrorMessage(event.getComponent().getClientId(facesContext),
                                                        cause.getMessage());
                                } else {
                                        throw (AbortProcessingException) cause;
                                }
                        } catch (RuntimeException e) {
                                throw new FacesException("Error calling action method of component with id "
                                                + event.getComponent().getClientId(facesContext), e);
                        }
                }

                NavigationHandler navigationHandler = application.getNavigationHandler();
                navigationHandler.handleNavigation(facesContext, fromAction, outcome);
                
                // Render Response if needed
                facesContext.renderResponse();
        }

}

监听器配置，faces-config-application.xml：

<application>        <variable-resolver>org.springframework.web.jsf.DelegatingVariableResolver</variable-resolver>
                 <message-bundle>resources.application</message-bundle>
                <locale-config>
                        <default-locale>en</default-locale>
                </locale-config>
                <action-listener>org.snailportal.webframework.listener.GlobalActionListener</action-listener>
</application>

这样，开发人员只需要在action和managed bean里面根据业务的需要抛出指定基础类型的Exception实例，由BaseAction和ActionListener完成错误的封装处理，再传递给前台进行显示，从而减少开发的代码量，提高框架的可维护性。

请问一下AppException是在哪个JAR下面
我编译通不过
谢谢