package?org.com.filter;

import?java.io.IOException;
import?java.util.Map;

import?javax.servlet.Filter;
import?javax.servlet.FilterChain;
import?javax.servlet.FilterConfig;
import?javax.servlet.ServletException;
import?javax.servlet.ServletRequest;
import?javax.servlet.ServletResponse;
import?javax.servlet.http.HttpServletRequest;
import?javax.servlet.http.HttpServletResponse;
import?javax.servlet.http.HttpSession;

import?org.apache.log4j.Logger;
import?org.com.command.role.GoupdateRoleCmd;

public?class?SingleFilter?implements?Filter?{
	private?static?Logger?log?=?Logger.getLogger（SingleFilter.class）;
	private?FilterConfig?filterConfig;

	public?void?doFilter（ServletRequest?req?ServletResponse?res
			FilterChain?chain）?throws?IOException?ServletException?{
		HttpServletRequest?request?=?（HttpServletRequest）?req;
		HttpServletResponse?response?=?（HttpServletResponse）?res;
		HttpSession?session?=?request.getSession（）;

		/**
		?*?如果用戶沒有登陸，則登陸，并將登陸信息放到application，
		?*?

		?*?信息為用戶id，用戶sessionid，用戶登陸時間，登陸IP
		?*?

		?*?如果用戶已登陸，則每次請求要檢查application，
		?*?

		?*?一旦用戶id相同而sessionid不同，即表明該用戶在其它地方登陸，
		?*?

		?*?當前登陸無條件注銷
		?*?

		?*?注銷過程為：將當前session失效，轉到登陸頁面，
		?*?

		?*?提示用戶該用戶id已在哪臺機器什么時間登陸了，當前登陸已注銷
		?*/
		boolean?isLogin?=?session.getAttribute（“NAME“）?!=?null;
		log.info（“----SingleFilter.isLogin?=?“+isLogin）;
		if?（isLogin）?{
			String?username?=?（String）?session.getAttribute（“NAME“）;
			String?curSessionid?=?session.getId（）;
			Map?single?=?（Map）?session.getAttribute（
					“single“）;
			if?（single?==?null）?{
				log.info（“----SingleFilter?single?==?null?:?“+single?==?null）;
				return;
			}
			Map?userMap?=?（Map）?single.get（username）;
			//?如果已經有登陸信息
			if?（userMap?!=?null）?{
				log.info（“----SingleFilter.userMap?!=?null“）;
				String?hisSesssionid?=?（String）?userMap.get（“sessionid“）;
				String?ip?=?（String）?userMap.get（“ip“）;
				String?date1?=?（String）?userMap.get（“date1“）;
				if?（!curSessionid.equals（hisSesssionid））?{
					String?jspMess?=?username?+?“已于“?+?date1?+?“從“?+?ip
							+?“登陸到了服務器上，當前登陸已被注銷！“;
					request.setAttribute（“ERROR“?jspMess）;
					session.removeAttribute（“NAME“）;
					session.invalidate（）;
					filterConfig.getServletContext（）.getRequestDispatcher（
							“/main.jsp“）.forward（request?response）;
					return;
				}
				log.info（“----SingleFilter.hisSessionid?not?null!“）;
			}
		}

		chain.doFilter（request?response）;
	}

	public?void?destroy（）?{
	}

	public?void?init（FilterConfig?filterConfig）?throws?ServletException?{
		this.filterConfig?=?filterConfig;
	}

}