shiro的源码学习（二）（ Session session = getSession()）

(1)在DelegatingSubject类中可以获取Session:

1  public Session getSession(boolean create) {
2       .......
3       SessionContext sessionContext = createSessionContext();
4       Session session = this.securityManager.start(sessionContext);
5       this.session = decorate(session);
6       .......
7       return this.session;
8 
9 }

(2)SecurityManager委托sessionManager(DefaultSessionManage)处理Session的创建:

1 public Session start(SessionContext context) throws AuthorizationException {
2     return this.sessionManager.start(context);
3     }

*注意：DefaultSessionManage的内部架构为：

(3)AbstractNativeSessionManager创建Session并管理Session:

1    public Session start(SessionContext context) {
2         Session session = createSession(context);
3         applyGlobalSessionTimeout(session);
4         onStart(session, context);
5         notifyStart(session);
6         //Don't expose the EIS-tier Session object to the client-tier:
7         return createExposedSession(session, context);
8     }

(4)到此Session的创建完成，及细节代码如下：AbstractNativeSessionManager交给AbstractValidatingSessionManager处理：

 1  protected Session createSession(SessionContext context) throws AuthorizationException {
 2         enableSessionValidationIfNecessary();
 3         return doCreateSession(context);
 4     }
 5 //
 6 private void enableSessionValidationIfNecessary() {
 7         SessionValidationScheduler scheduler = getSessionValidationScheduler();
 8         if (isSessionValidationSchedulerEnabled() && (scheduler == null || !scheduler.isEnabled())) {
 9             enableSessionValidation();
10         }
11     }
12 //
13 protected void enableSessionValidation() {
14         SessionValidationScheduler scheduler = getSessionValidationScheduler();
15         if (scheduler == null) {
16             scheduler = createSessionValidationScheduler();//scheduler = new ExecutorServiceSessionValidationScheduler(this);scheduler.setInterval(getSessionValidationInterval());
17             setSessionValidationScheduler(scheduler);
18         }
19         if (log.isInfoEnabled()) {
20             log.info("Enabling session validation scheduler...");
21         }
22         scheduler.enableSessionValidation();
23         afterSessionValidationEnabled();
24     }
25

(5)ExecutorServiceSessionValidationScheduler验证Session的过期：

 1 /**
 2      * Creates a single thread {@link ScheduledExecutorService} to validate sessions at fixed intervals 
 3      * and enables this scheduler. The executor is created as a daemon thread to allow JVM to shut down
 4      */
 5     //TODO Implement an integration test to test for jvm exit as part of the standalone example
 6     // (so we don't have to change the unit test execution model for the core module)
 7     public void enableSessionValidation() {
 8         if (this.interval > 0l) {
 9             this.service = Executors.newSingleThreadScheduledExecutor(new ThreadFactory() {  
10             public Thread newThread(Runnable r) {  
11                 Thread thread = new Thread(r);  
12                 thread.setDaemon(true);  
13                 return thread;  
14                 }  
15             });                  
16             this.service.scheduleAtFixedRate(this, interval, interval, TimeUnit.MILLISECONDS);
17             this.enabled = true;
18         }
19     }
20 
21     public void run() {
22         if (log.isDebugEnabled()) {
23             log.debug("Executing session validation...");
24         }
25         long startTime = System.currentTimeMillis();
26         this.sessionManager.validateSessions();
27         long stopTime = System.currentTimeMillis();
28         if (log.isDebugEnabled()) {
29             log.debug("Session validation completed successfully in " + (stopTime - startTime) + " milliseconds.");
30         }
31     }

(6)AbstractValidatingSessionManager验证Session的过期：

    /**
     * @see ValidatingSessionManager#validateSessions()
     */
    public void validateSessions() {
        if (log.isInfoEnabled()) {
            log.info("Validating all active sessions...");
        }

        int invalidCount = 0;

        Collection<Session> activeSessions = getActiveSessions();

        if (activeSessions != null && !activeSessions.isEmpty()) {
            for (Session s : activeSessions) {
                try {
                    //simulate a lookup key to satisfy the method signature.
                    //this could probably stand to be cleaned up in future versions:
                    SessionKey key = new DefaultSessionKey(s.getId());
                    validate(s, key);
                } catch (InvalidSessionException e) {
                    if (log.isDebugEnabled()) {
                        boolean expired = (e instanceof ExpiredSessionException);
                        String msg = "Invalidated session with id [" + s.getId() + "]" +
                                (expired ? " (expired)" : " (stopped)");
                        log.debug(msg);
                    }
                    invalidCount++;
                }
            }
        }

        if (log.isInfoEnabled()) {
            String msg = "Finished session validation.";
            if (invalidCount > 0) {
                msg += "  [" + invalidCount + "] sessions were stopped.";
            } else {
                msg += "  No sessions were stopped.";
            }
            log.info(msg);
        }
    }
//类DefaultSessionManager实现getActiveSessions接口
    protected abstract Collection<Session> getActiveSessions();

protected Collection<Session> getActiveSessions() {
        Collection<Session> active = sessionDAO.getActiveSessions();
        return active != null ? active : Collections.<Session>emptySet();
    }

(7)Session的校验完成，接下来是DefaultSessionManager进行Session的创建：

protected Session doCreateSession(SessionContext context) {
        Session s = newSessionInstance(context);
        if (log.isTraceEnabled()) {
            log.trace("Creating session for host {}", s.getHost());
         }
        create(s);
        return s;
     }

protected Session newSessionInstance(SessionContext context) {
return getSessionFactory().createSession(context);
}

protected void create(Session session) {
if (log.isDebugEnabled()) {
log.debug("Creating new EIS record for new session instance [" + session + "]");
}
sessionDAO.create(session);
}

(8)DefaultSessionManager委托Session(MemorySessionDAO)维护Session:

1     protected Serializable doCreate(Session session) {
2         Serializable sessionId = generateSessionId(session);
3         assignSessionId(session, sessionId);
4         storeSession(sessionId, session);
5         return sessionId;
6     }

protected Session storeSession(Serializable id, Session session) {
if (id == null) {
throw new NullPointerException("id argument cannot be null.");
}
return sessions.putIfAbsent(id, session);
}

(9) 创建并维护Session之后，AbstractNativeSessionManager交给注册好的监听器，监听器调用启动onStart接口

1     protected void notifyStart(Session session) {
2         for (SessionListener listener : this.listeners) {
3             listener.onStart(session);
4         }
5     }

(10)最后创建委托Session,

protected Session createExposedSession(Session session, SessionContext context) {
        return new DelegatingSession(this, new DefaultSessionKey(session.getId()));
    }

(11)最后Subject创建自己的代理Session，主要用来拦截stop方法：

 1     protected Session decorate(Session session) {
 2          if (session == null) {
 3              throw new IllegalArgumentException("session cannot be null");
 4          }
 5          return new StoppingAwareProxiedSession(session, this);
 6      }
 7     private class StoppingAwareProxiedSession extends ProxiedSession {
 8 
 9            private final DelegatingSubject owner;
10 
11            private StoppingAwareProxiedSession(Session target, DelegatingSubject owningSubject) {
12                 super(target);
13                 owner = owningSubject;
14             }
15 
16            public void stop() throws InvalidSessionException {
17            super.stop();
18            owner.sessionStopped();
19          }
20        }

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shiro的源码学习（二）（ Session session = getSession()）