protected void doService()

in tapestry-framework/src/org/apache/tapestry/ApplicationServlet.java [141:251]
63 lines of code
14 McCabe index (conditional complexity)

    protected void doService(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException
    {
        RequestContext context = null;

        try
        {
            // Create a context from the various bits and pieces.

            context = createRequestContext(request, response);

            // The subclass provides the engine.

            IEngine engine = getEngine(context);

            if (engine == null)
                throw new ServletException(
                        Tapestry.getMessage("ApplicationServlet.could-not-locate-engine"));

            boolean dirty = engine.service(context);

            HttpSession session = context.getSession();

            // When there's an active session, we *may* store it into
            // the HttpSession and we *will not* store the engine
            // back into the engine pool.

            if (session != null)
            {
                // If the service may have changed the engine and the
                // special storeEngine flag is on, then re-save the engine
                // into the session.  Otherwise, we only save the engine
                // into the session when the session is first created (is new).

                try
                {

                    boolean forceStore =
                            engine.isStateful() && (session.getAttribute(_attributeName) == null);

                    if (forceStore || dirty)
                    {
                        if (LOG.isDebugEnabled())
                            LOG.debug("Storing " + engine + " into session as " + _attributeName);

                        session.setAttribute(_attributeName, engine);
                    }
                }
                catch (IllegalStateException ex)
                {
                    // Ignore because the session been's invalidated.
                    // Allow the engine (which has state particular to the client)
                    // to be reclaimed by the garbage collector.

                    if (LOG.isDebugEnabled())
                        LOG.debug("Session invalidated.");
                }

                // The engine is stateful and stored in a session.  Even if it started
                // the request cycle in the pool, it doesn't go back.

                return;
            }

            if (engine.isStateful())
            {
                LOG.error(
                        Tapestry.format(
                                "ApplicationServlet.engine-stateful-without-session",
                                engine));
                return;
            }

            // No session; the engine contains no state particular to
            // the client (except for locale).  Don't throw it away,
            // instead save it in a pool for later reuse (by this, or another
            // client in the same locale).

            if (LOG.isDebugEnabled())
                LOG.debug("Returning " + engine + " to pool.");

            _enginePool.store(engine.getLocale(), engine);

        }
        catch (ServletException ex)
        {
            log("ServletException", ex);

            show(ex);

            // Rethrow it.

            throw ex;
        }
        catch (IOException ex)
        {
            log("IOException", ex);

            show(ex);

            // Rethrow it.

            throw ex;
        }
        finally
        {
            if (context != null)
                context.cleanup();
        }

    }