apache shiro （8）并发登录人数控制

妖狐艹你老母 2023-07-09 13:28 23阅读 0赞

package com.github.zhangkaitao.shiro.chapter18.web.shiro.filter;
    
    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 javax.servlet.ServletRequest;
    import javax.servlet.ServletResponse;
    import java.io.Serializable;
    import java.util.Deque;
    import java.util.LinkedList;
    
    /**
     * <p>User: Zhang Kaitao
     * <p>Date: 14-2-18
     * <p>Version: 1.0
     */
    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();
            String username = (String) subject.getPrincipal();
            Serializable sessionId = session.getId();
    
            //TODO 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);
                WebUtils.issueRedirect(request, response, kickoutUrl);
                return false;
            }
    
            return true;
        }
    }