Something
public text v1 · immutable//FROM CLASS A
private static Map<String, Long> lastNotificationMap = new HashMap<String, Long>();
//FROM CLASS B
ServletContext servletContext = this.getServlet().getServletContext();
Map<String, Long> lastNotificationMap = (Map<String, Long>) servletContext.getAttribute("lastNotificationMap");
String lastNotificationKey = pVO.getTagId() + "-" + pVO.getPerfId();
long lastNotificationTS = lastNotificationMap.get(lastNotificationKey);