Shiro - 限制并发人数登录与剔除

import org.apache.shiro.cache.Cache;

import org.apache.shiro.cache.CacheManager;

import org.apache.shiro.session.Session;

import org.apache.shiro.session.mgt.DefaultSessionKey;

import org.apache.shiro.session.mgt.SessionManager;

import org.apache.shiro.subject.Subject;

import org.apache.shiro.web.filter.AccessControlFilter;

import org.apache.shiro.web.util.WebUtils;

import com.agood.pojo.ActiveUser;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.Serializable;

import java.util.Deque;

import java.util.LinkedList;

/**

 *

 * @Title: KickoutSessionControlFilter.java

 * @Package com.agood.bejavagod.controller.filter

 * @Description: 同一用户后登陆踢出前面的用户

 * Copyright: Copyright (c) 2016

 * Company:Nathan.Lee.Salvatore

 *

 * @author leechenxiang

 * @date 2016年12月12日 下午7:25:40

 * @version V1.0

 */

public class KickoutSessionControlFilter extends AccessControlFilter {

    private String kickoutUrl; //踢出后到的地址

    private boolean kickoutAfter = false; //踢出之前登录的/之后登录的用户 默认踢出之前登录的用户

    private int maxSession = 1; //同一个帐号最大会话数 默认1

    private SessionManager sessionManager;

    private Cache<String, Deque<Serializable>> cache;

    public void setKickoutUrl(String kickoutUrl) {

        this.kickoutUrl = kickoutUrl;

    }

    public void setKickoutAfter(boolean kickoutAfter) {

        this.kickoutAfter = kickoutAfter;

    }

    public void setMaxSession(int maxSession) {

        this.maxSession = maxSession;

    }

    public void setSessionManager(SessionManager sessionManager) {

        this.sessionManager = sessionManager;

    }

    public void setCacheManager(CacheManager cacheManager) {

        this.cache = cacheManager.getCache("shiro-kickout-session");

    }

    @Override

    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception {

        return false;

    }

    @Override

    protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {

        Subject subject = getSubject(request, response);

        if(!subject.isAuthenticated() && !subject.isRemembered()) {

            //如果没有登录，直接进行之后的流程

            return true;

        }

        Session session = subject.getSession();

        ActiveUser user = (ActiveUser)subject.getPrincipal();

        String username = user.getUserName();

        Serializable sessionId = session.getId();

        // 同步控制

        Deque<Serializable> deque = cache.get(username);

        if(deque == null) {

            deque = new LinkedList<Serializable>();

            cache.put(username, deque);

        }

        //如果队列里没有此sessionId，且用户没有被踢出；放入队列

        if(!deque.contains(sessionId) && session.getAttribute("kickout") == null) {

            deque.push(sessionId);

        }

        //如果队列里的sessionId数超出最大会话数，开始踢人

        while(deque.size() > maxSession) {

            Serializable kickoutSessionId = null;

            if(kickoutAfter) { //如果踢出后者

                kickoutSessionId = deque.removeFirst();

            } else { //否则踢出前者

                kickoutSessionId = deque.removeLast();

            }

            try {

                Session kickoutSession = sessionManager.getSession(new DefaultSessionKey(kickoutSessionId));

                if(kickoutSession != null) {

                    //设置会话的kickout属性表示踢出了

                    kickoutSession.setAttribute("kickout", true);

                }

            } catch (Exception e) {//ignore exception

            }

        }

        //如果被踢出了，直接退出，重定向到踢出后的地址

        if (session.getAttribute("kickout") != null) {

            //会话被踢出了

            try {

                subject.logout();

            } catch (Exception e) { //ignore

            }

            saveRequest(request);

            HttpServletRequest httpRequest = WebUtils.toHttp(request);

            if (ShiroFilterUtils.isAjax(httpRequest)) {

                HttpServletResponse httpServletResponse = WebUtils.toHttp(response);

                httpServletResponse.sendError(ShiroFilterUtils.HTTP_STATUS_SESSION_EXPIRE);

                return false;

            } else {

                WebUtils.issueRedirect(request, response, kickoutUrl);

                return false;

            }

        }

        return true;

    }

}

<property name="filters">

            <map>

                <entry key="kickout" value-ref="kickoutSessionControlFilter"/>

            </map>

        </property>

<bean id="kickoutSessionControlFilter" class="com.agood.bejavagod.controller.filter.KickoutSessionControlFilter">

        <property name="cacheManager" ref="shiroEhcacheManager"/>

        <property name="sessionManager" ref="sessionManager"/>

        <!-- 是否踢出后来登录的，默认是false；即后者登录的用户踢出前者登录的用户 -->

        <property name="kickoutAfter" value="false"/>

        <!-- 同一个用户最大的会话数，默认1；比如2的意思是同一个用户允许最多同时两个人登录 -->

        <property name="maxSession" value="1"/>

        <property name="kickoutUrl" value="/login.action"/>

    </bean>

/** = kickout,authc