applicationdispatcher.java

业界著名的tomcat服务器的最新6.0的源代码。

            if ( log.isDebugEnabled() )
                log.debug(" Non-HTTP Forward");
            
            processRequest(hrequest,hresponse,state);

        }

        // Handle an HTTP named dispatcher forward
        else if ((servletPath == null) && (pathInfo == null)) {

            if ( log.isDebugEnabled() )
                log.debug(" Named Dispatcher Forward");
            
            ApplicationHttpRequest wrequest =
                (ApplicationHttpRequest) wrapRequest(state);
            wrequest.setRequestURI(hrequest.getRequestURI());
            wrequest.setContextPath(hrequest.getContextPath());
            wrequest.setServletPath(hrequest.getServletPath());
            wrequest.setPathInfo(hrequest.getPathInfo());
            wrequest.setQueryString(hrequest.getQueryString());

            processRequest(request,response,state);

            wrequest.recycle();
            unwrapRequest(state);

        }

        // Handle an HTTP path-based forward
        else {

            if ( log.isDebugEnabled() )
                log.debug(" Path Based Forward");

            ApplicationHttpRequest wrequest =
                (ApplicationHttpRequest) wrapRequest(state);
            String contextPath = context.getPath();

            if (hrequest.getAttribute(Globals.FORWARD_REQUEST_URI_ATTR) == null) {
                wrequest.setAttribute(Globals.FORWARD_REQUEST_URI_ATTR,
                                      hrequest.getRequestURI());
                wrequest.setAttribute(Globals.FORWARD_CONTEXT_PATH_ATTR,
                                      hrequest.getContextPath());
                wrequest.setAttribute(Globals.FORWARD_SERVLET_PATH_ATTR,
                                      hrequest.getServletPath());
                wrequest.setAttribute(Globals.FORWARD_PATH_INFO_ATTR,
                                      hrequest.getPathInfo());
                wrequest.setAttribute(Globals.FORWARD_QUERY_STRING_ATTR,
                                      hrequest.getQueryString());
            }
 
            wrequest.setContextPath(contextPath);
            wrequest.setRequestURI(requestURI);
            wrequest.setServletPath(servletPath);
            wrequest.setPathInfo(pathInfo);
            if (queryString != null) {
                wrequest.setQueryString(queryString);
                wrequest.setQueryParams(queryString);
            }

            processRequest(request,response,state);

            wrequest.recycle();
            unwrapRequest(state);

        }

        // This is not a real close in order to support error processing
        if ( log.isDebugEnabled() )
            log.debug(" Disabling the response for futher output");

        if  (response instanceof ResponseFacade) {
            ((ResponseFacade) response).finish();
        } else {
            // Servlet SRV.6.2.2. The Resquest/Response may have been wrapped
            // and may no longer be instance of RequestFacade 
            if (log.isDebugEnabled()){
                log.debug( " The Response is vehiculed using a wrapper: " 
                           + response.getClass().getName() );
            }

            // Close anyway
            try {
                PrintWriter writer = response.getWriter();
                writer.close();
            } catch (IllegalStateException e) {
                try {
                    ServletOutputStream stream = response.getOutputStream();
                    stream.close();
                } catch (IllegalStateException f) {
                    ;
                } catch (IOException f) {
                    ;
                }
            } catch (IOException e) {
                ;
            }
        }

    }

    
    /**
     * Prepare the request based on the filter configuration.
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     * @param state The RD state
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    private void processRequest(ServletRequest request, 
                                ServletResponse response,
                                State state)
        throws IOException, ServletException {
                
        Integer disInt = (Integer) request.getAttribute
            (ApplicationFilterFactory.DISPATCHER_TYPE_ATTR);
        if (disInt != null) {
            if (disInt.intValue() != ApplicationFilterFactory.ERROR) {
                state.outerRequest.setAttribute
                    (ApplicationFilterFactory.DISPATCHER_REQUEST_PATH_ATTR,
                     servletPath);
                state.outerRequest.setAttribute
                    (ApplicationFilterFactory.DISPATCHER_TYPE_ATTR,
                     Integer.valueOf(ApplicationFilterFactory.FORWARD));
                invoke(state.outerRequest, response, state);
            } else {
                invoke(state.outerRequest, response, state);
            }
        }

    }
    
    
    
    /**
     * Include the response from another resource in the current response.
     * Any runtime exception, IOException, or ServletException thrown by the
     * called servlet will be propogated to the caller.
     *
     * @param request The servlet request that is including this one
     * @param response The servlet response to be appended to
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet exception occurs
     */
    public void include(ServletRequest request, ServletResponse response)
        throws ServletException, IOException
    {
        if (Globals.IS_SECURITY_ENABLED) {
            try {
                PrivilegedInclude dp = new PrivilegedInclude(request,response);
                AccessController.doPrivileged(dp);
            } catch (PrivilegedActionException pe) {
                Exception e = pe.getException();

                if (e instanceof ServletException)
                    throw (ServletException) e;
                throw (IOException) e;
            }
        } else {
            doInclude(request,response);
        }
    }

    private void doInclude(ServletRequest request, ServletResponse response)
        throws ServletException, IOException
    {
        // Set up to handle the specified request and response
        State state = new State(request, response, true);

        if (Globals.STRICT_SERVLET_COMPLIANCE) {
            // Check SRV.8.2 / SRV.14.2.5.1 compliance
            checkSameObjects(request, response);
        }
        
        // Create a wrapped response to use for this request
        wrapResponse(state);

        // Handle a non-HTTP include
        if (!(request instanceof HttpServletRequest) ||
            !(response instanceof HttpServletResponse)) {

            if ( log.isDebugEnabled() )
                log.debug(" Non-HTTP Include");
            request.setAttribute(ApplicationFilterFactory.DISPATCHER_TYPE_ATTR,
                    Integer.valueOf(ApplicationFilterFactory.INCLUDE));
            request.setAttribute(
                    ApplicationFilterFactory.DISPATCHER_REQUEST_PATH_ATTR,
                    servletPath);
            invoke(request, state.outerResponse, state);
        }

        // Handle an HTTP named dispatcher include
        else if (name != null) {

            if ( log.isDebugEnabled() )
                log.debug(" Named Dispatcher Include");

            ApplicationHttpRequest wrequest =
                (ApplicationHttpRequest) wrapRequest(state);
            wrequest.setAttribute(Globals.NAMED_DISPATCHER_ATTR, name);
            if (servletPath != null)
                wrequest.setServletPath(servletPath);
            wrequest.setAttribute(ApplicationFilterFactory.DISPATCHER_TYPE_ATTR,
                    Integer.valueOf(ApplicationFilterFactory.INCLUDE));
            wrequest.setAttribute(
                    ApplicationFilterFactory.DISPATCHER_REQUEST_PATH_ATTR,
                    servletPath);
            invoke(state.outerRequest, state.outerResponse, state);

            wrequest.recycle();
        }

        // Handle an HTTP path based include
        else {

            if ( log.isDebugEnabled() )
                log.debug(" Path Based Include");

            ApplicationHttpRequest wrequest =
                (ApplicationHttpRequest) wrapRequest(state);
            String contextPath = context.getPath();
            if (requestURI != null)
                wrequest.setAttribute(Globals.INCLUDE_REQUEST_URI_ATTR,
                                      requestURI);
            if (contextPath != null)
                wrequest.setAttribute(Globals.INCLUDE_CONTEXT_PATH_ATTR,
                                      contextPath);
            if (servletPath != null)
                wrequest.setAttribute(Globals.INCLUDE_SERVLET_PATH_ATTR,
                                      servletPath);
            if (pathInfo != null)
                wrequest.setAttribute(Globals.INCLUDE_PATH_INFO_ATTR,
                                      pathInfo);
            if (queryString != null) {
                wrequest.setAttribute(Globals.INCLUDE_QUERY_STRING_ATTR,
                                      queryString);
                wrequest.setQueryParams(queryString);
            }
            
            wrequest.setAttribute(ApplicationFilterFactory.DISPATCHER_TYPE_ATTR,
                    Integer.valueOf(ApplicationFilterFactory.INCLUDE));
            wrequest.setAttribute(
                    ApplicationFilterFactory.DISPATCHER_REQUEST_PATH_ATTR,
                    servletPath);
            invoke(state.outerRequest, state.outerResponse, state);

            wrequest.recycle();
        }

    }


    // -------------------------------------------------------- Private Methods


    /**
     * Ask the resource represented by this RequestDispatcher to process
     * the associated request, and create (or append to) the associated
     * response.
     * <p>
     * <strong>IMPLEMENTATION NOTE</strong>: This implementation assumes
     * that no filters are applied to a forwarded or included resource,
     * because they were already done for the original request.
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    private void invoke(ServletRequest request, ServletResponse response,
            State state) throws IOException, ServletException {

        // Checking to see if the context classloader is the current context
        // classloader. If it's not, we're saving it, and setting the context
        // classloader to the Context classloader
        ClassLoader oldCCL = Thread.currentThread().getContextClassLoader();
        ClassLoader contextClassLoader = context.getLoader().getClassLoader();

        if (oldCCL != contextClassLoader) {
            Thread.currentThread().setContextClassLoader(contextClassLoader);
        } else {
            oldCCL = null;
        }

        // Initialize local variables we may need
        HttpServletResponse hresponse = (HttpServletResponse) response;
        Servlet servlet = null;
        IOException ioException = null;
        ServletException servletException = null;
        RuntimeException runtimeException = null;
        boolean unavailable = false;

        // Check for the servlet being marked unavailable
        if (wrapper.isUnavailable()) {
            wrapper.getLogger().warn(
                    sm.getString("applicationDispatcher.isUnavailable", 
                    wrapper.getName()));
            long available = wrapper.getAvailable();
            if ((available > 0L) && (available < Long.MAX_VALUE))
                hresponse.setDateHeader("Retry-After", available);
            hresponse.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE, sm
                    .getString("applicationDispatcher.isUnavailable", wrapper
                            .getName()));
            unavailable = true;
        }

        // Allocate a servlet instance to process this request
        try {
            if (!unavailable) {
                servlet = wrapper.allocate();
            }
        } catch (ServletException e) {
            wrapper.getLogger().error(sm.getString("applicationDispatcher.allocateException",
                             wrapper.getName()), StandardWrapper.getRootCause(e));
            servletException = e;
            servlet = null;
        } catch (Throwable e) {
            wrapper.getLogger().error(sm.getString("applicationDispatcher.allocateException",
                             wrapper.getName()), e);
            servletException = new ServletException
                (sm.getString("applicationDispatcher.allocateException",
                              wrapper.getName()), e);
            servlet = null;
        }
                
        // Get the FilterChain Here
        ApplicationFilterFactory factory = ApplicationFilterFactory.getInstance();
        ApplicationFilterChain filterChain = factory.createFilterChain(request,
                                                                wrapper,servlet);
        // Call the service() method for the allocated servlet instance
        try {
            String jspFile = wrapper.getJspFile();
            if (jspFile != null)
                request.setAttribute(Globals.JSP_FILE_ATTR, jspFile);
            else
                request.removeAttribute(Globals.JSP_FILE_ATTR);