如何从BayeuxServer.SessionListener内部访问ServletContext？

public class MySessionListener implements BayeuxServer.SessionListener, ServletContextListener {
    private ServletContext servletContext;

    @Override
    public void sessionAdded(ServerSession session, ServerMessage message) {
        // 在这里访问ServletContext对象
        if (servletContext != null) {
            // 执行相关操作
        }
    }

    @Override
    public void sessionRemoved(ServerSession session, boolean timedout) {
        // 在这里访问ServletContext对象
        if (servletContext != null) {
            // 执行相关操作
        }
    }

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        servletContext = sce.getServletContext();
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        servletContext = null;
    }
}

<listener>
    <listener-class>com.example.MySessionListener</listener-class>
</listener>