[Java]Fobid multiple login

if (isLogin) {
   //Forbid Multiple Login
   //User login success, refresh session map, if multiple login, make the exists session invalid 
   String sessionIdFromMap = SessionListener.userMap.get(portalLoginName);
   String sessionIdFromReq = request.getSession().getId();
   logger.debug("-------Session ID from user map: {}---------", sessionIdFromMap);
   logger.debug("-------Session ID from request: {}---------", sessionIdFromReq);

            if(sessionIdFromMap != null&&!sessionIdFromMap.equals("")){
              if(sessionIdFromMap.equals(sessionIdFromReq)){
                     logger.debug("======session map equals request session id=====");
          SessionListener.sessionMap.get(sessionIdFromMap).invalidate();
          SessionListener.userMap.put(portalLoginName, sessionIdFromReq);
          SessionListener.sessionMap.put(sessionIdFromReq, request.getSession());
          
         }else{
          if (SessionListener.userMap.containsKey(portalLoginName)) {
           logger.debug("=========the same user multiple login=========");
           SessionListener.sessionMap.get(sessionIdFromMap).invalidate();
              SessionListener.userMap.put(portalLoginName, sessionIdFromReq);
              SessionListener.sessionMap.put(sessionIdFromReq, request.getSession());
          }
         }
            logger.debug("=====new session to put into map====");
            SessionListener.userMap.put(portalLoginName,request.getSession().getId());
            SessionListener.sessionMap.put(request.getSession().getId(),request.getSession());
....
}

 

listener:

public class SessionListener implements HttpSessionListener {

	private static final Logger logger = LoggerFactory.getLogger(SessionListener.class);
	
	public static Map<String, String> userMap = new HashMap<>();
	public static Map<String, HttpSession> sessionMap = new HashMap<>();

	@Override
	public void sessionCreated(HttpSessionEvent se) {
		// TODO Auto-generated method stub

	}

	@Override
	public void sessionDestroyed(HttpSessionEvent se) {
		HttpSession session = se.getSession();
		String sessionId = session.getId();
		logger.debug("-------------session[{}] destroy---------", sessionId);
		sessionMap.remove(sessionId);
		for (String key : userMap.keySet()) {
			if (userMap.get(key).equals(sessionId)) {
				userMap.remove(key);
			}
		}
	}

}

 web.xml:

<listener>
  	<listener-class>com.hkt.umg.unified.portal.web.SessionListener</listener-class>
  </listener>

 

思路:

1.如果第一次登陆,记录登陆的session id

2.如果第二次登陆的session id和第一次相同,而且登录名也一样,则清除掉第一次的session;若session id不同则记录第二次的session id

 

参考:

https://blog.csdn.net/football98/article/details/52777575