如何为JSF中的不同PROJECT_STAGE获取不同的错误页面

<error-page>
    <exception-type>java.lang.Throwable</exception-type>
    <location>/error.xhtml</location>
</error-page>

<system-event-listener>
    <system-event-listener-class>com.example.ErrorPageListener</system-event-listener-class>
    <system-event-class>javax.faces.event.ExceptionQueuedEvent</system-event-class>
    <source-class>javax.faces.application.ProjectStage</source-class>
</system-event-listener>

public class ErrorPageListener implements SystemEventListener {
    @Override
    public void processEvent(SystemEvent event) throws AbortProcessingException {
        ProjectStage projectStage = ProjectStage.getCurrentStage(FacesContext.getCurrentInstance());
        String errorPage = null;
        
        if (projectStage == ProjectStage.Development) {
            errorPage = "/error_dev.xhtml";
        } else if (projectStage == ProjectStage.Production) {
            errorPage = "/error_prod.xhtml";
        } else if (projectStage == ProjectStage.SystemTest) {
            errorPage = "/error_test.xhtml";
        }
        
        ExternalContext externalContext = FacesContext.getCurrentInstance().getExternalContext();
        externalContext.getRequestMap().put("javax.servlet.error.status_code", 500);
        externalContext.getRequestMap().put("javax.servlet.error.exception_type", Throwable.class);
        externalContext.getRequestMap().put("javax.servlet.error.message", "Internal Server Error");
        externalContext.dispatch(errorPage);
    }

    @Override
    public boolean isListenerForSource(Object source) {
        return source instanceof ProjectStage;
    }
}