疯狂的菠菜

static
    {
        try
        {
            continuationClass = LocalUtil.classForName("org.mortbay.util.ajax.Continuation"); //$NON-NLS-1$
            suspendMethod = continuationClass.getMethod("suspend", new Class[] { Long.TYPE }); //$NON-NLS-1$
            resumeMethod = continuationClass.getMethod("resume", new Class[] {}); //$NON-NLS-1$
            getObject = continuationClass.getMethod("getObject", new Class[] {}); //$NON-NLS-1$
            setObject = continuationClass.getMethod("setObject", new Class[] { Object.class }); //$NON-NLS-1$
        }
        catch (Exception ex)
        {
            log.debug("No Jetty ContuniationSupport class, using standard Servlet API"); //$NON-NLS-1$
        }
    }

public void pollPreStreamWait()
    {
        WebContext context = WebContextFactory.get();
        Container container = context.getContainer();

        final ScriptSession scriptSession = context.getScriptSession();
        ServerLoadMonitor monitor = (ServerLoadMonitor) container.getBean(ServerLoadMonitor.class.getName());
        long sleepTime = monitor.timeWithinPollPreStream();

        synchronized (scriptSession.getScriptLock())
        {
            // Don't wait if there are queued scripts
            if (scriptSession.getQueuedScripts() > 0)
            {
                return;
            }

            // If this is Jetty then we can use Continuations
            HttpServletRequest request = context.getHttpServletRequest();

            boolean useSleep = true;
            Object continuation = request.getAttribute(ATTRIBUTE_JETTY_CONTINUATION);
            if (continuation != null)
            {
                useSleep = false;

                try
                {
                    // create a listener 
                    ScriptConduit listener = (ScriptConduit) getObject.invoke(continuation, new Object[0]);
                    if (listener == null)
                    {
                        listener = new SystemScriptConduit(continuation);
                        setObject.invoke(continuation, new Object[] { listener });
                    }
                    scriptSession.addScriptConduit(listener);

                    // continuation.suspend(sleepTime);
                    // NB. May throw a Runtime exception that must propogate to the container!
                    suspendMethod.invoke(continuation, new Object[] { new Long(sleepTime) });
                }
                catch (InvocationTargetException ex)
                {
                    ContinuationUtil.rethrowIfContinuation(ex.getTargetException());

                    log.warn("Error in Reflection", ex.getTargetException()); //$NON-NLS-1$
                    useSleep = true;
                }
                catch (Exception ex)
                {
                    log.warn("Exception", ex); //$NON-NLS-1$
                    useSleep = true;
                }
            }

            if (useSleep)
            {
                // create a listener // TODO avoid the expense of creation and registration
                ScriptConduit listener = new ScriptConduit()
                {
                    public boolean addScript(String script)
                    {
                        try
                        {
                            synchronized (scriptSession.getScriptLock())
                            {
                                scriptSession.getScriptLock().notifyAll();
                            }
                        }
                        catch (Exception ex)
                        {
                            log.warn("Failed to notify all ScriptSession users", ex); //$NON-NLS-1$
                        }

                        // just listening!
                        return false;
                    }

                    public void flush()
                    {
                    }
                };
                scriptSession.addScriptConduit(listener);

                // The comet part of a poll request
                try
                {
                    scriptSession.getScriptLock().wait(sleepTime);
                }
                catch (InterruptedException ex)
                {
                    log.warn("Interupted", ex); //$NON-NLS-1$
                }
                finally
                {
                    scriptSession.removeScriptConduit(listener);
                }
            }
        }
    }