requestprocessor.java

structs源码

        // paths not starting with / should be passed through without any
        // processing (ie. they're absolute)
        if (forwardPath.startsWith("/")) {
            // get module relative uri
            uri = RequestUtils.forwardURL(request, forward, null);
        } else {
            uri = forwardPath;
        }

        if (forward.getRedirect()) {
            // only prepend context path for relative uri
            if (uri.startsWith("/")) {
                uri = request.getContextPath() + uri;
            }

            response.sendRedirect(response.encodeRedirectURL(uri));
        } else {
            doForward(uri, request, response);
        }
    }

    // :FIXME: if Action.execute throws Exception, and Action.process has been
    // removed, should the process* methods still throw IOException,
    // ServletException?

    /**
     * <P>Ask the specified <code>Action</code> instance to handle this
     * request. Return the <code>ActionForward</code> instance (if any)
     * returned by the called <code>Action</code> for further processing.
     * </P>
     *
     * @param request  The servlet request we are processing
     * @param response The servlet response we are creating
     * @param action   The Action instance to be used
     * @param form     The ActionForm instance to pass to this Action
     * @param mapping  The ActionMapping instance to pass to this Action
     * @return The <code>ActionForward</code> instance (if any) returned by
     *         the called <code>Action</code>.
     * @throws IOException      if an input/output error occurs
     * @throws ServletException if a servlet exception occurs
     */
    protected ActionForward processActionPerform(HttpServletRequest request,
        HttpServletResponse response, Action action, ActionForm form,
        ActionMapping mapping)
        throws IOException, ServletException {
        try {
            return (action.execute(mapping, form, request, response));
        } catch (Exception e) {
            return (processException(request, response, e, form, mapping));
        }
    }

    /**
     * <p>Removes any <code>ActionMessages</code> object stored in the session
     * under <code>Globals.MESSAGE_KEY</code> and <code>Globals.ERROR_KEY</code>
     * if the messages' <code>isAccessed</code> method returns true.  This
     * allows messages to be stored in the session, display one time, and be
     * released here.</p>
     *
     * @param request  The servlet request we are processing.
     * @param response The servlet response we are creating.
     * @since Struts 1.2
     */
    protected void processCachedMessages(HttpServletRequest request,
        HttpServletResponse response) {
        HttpSession session = request.getSession(false);

        if (session == null) {
            return;
        }

        // Remove messages as needed
        ActionMessages messages =
            (ActionMessages) session.getAttribute(Globals.MESSAGE_KEY);

        if (messages != null) {
            if (messages.isAccessed()) {
                session.removeAttribute(Globals.MESSAGE_KEY);
            }
        }

        // Remove error messages as needed
        messages = (ActionMessages) session.getAttribute(Globals.ERROR_KEY);

        if (messages != null) {
            if (messages.isAccessed()) {
                session.removeAttribute(Globals.ERROR_KEY);
            }
        }
    }

    /**
     * <p>Set the default content type (with optional character encoding) for
     * all responses if requested.  <strong>NOTE</strong> - This header will
     * be overridden automatically if a <code>RequestDispatcher.forward</code>
     * call is ultimately invoked.</p>
     *
     * @param request  The servlet request we are processing
     * @param response The servlet response we are creating
     */
    protected void processContent(HttpServletRequest request,
        HttpServletResponse response) {
        String contentType =
            moduleConfig.getControllerConfig().getContentType();

        if (contentType != null) {
            response.setContentType(contentType);
        }
    }

    /**
     * <p>Ask our exception handler to handle the exception. Return the
     * <code>ActionForward</code> instance (if any) returned by the called
     * <code>ExceptionHandler</code>.</p>
     *
     * @param request   The servlet request we are processing
     * @param response  The servlet response we are processing
     * @param exception The exception being handled
     * @param form      The ActionForm we are processing
     * @param mapping   The ActionMapping we are using
     * @return The <code>ActionForward</code> instance (if any) returned by
     *         the called <code>ExceptionHandler</code>.
     * @throws IOException      if an input/output error occurs
     * @throws ServletException if a servlet exception occurs
     */
    protected ActionForward processException(HttpServletRequest request,
        HttpServletResponse response, Exception exception, ActionForm form,
        ActionMapping mapping)
        throws IOException, ServletException {
        // Is there a defined handler for this exception?
        ExceptionConfig config = mapping.findException(exception.getClass());

        if (config == null) {
            log.warn(getInternal().getMessage("unhandledException",
                    exception.getClass()));

            if (exception instanceof IOException) {
                throw (IOException) exception;
            } else if (exception instanceof ServletException) {
                throw (ServletException) exception;
            } else {
                throw new ServletException(exception);
            }
        }

        // Use the configured exception handling
        try {
            ExceptionHandler handler =
                (ExceptionHandler) RequestUtils.applicationInstance(config
                    .getHandler());

            return (handler.execute(exception, config, mapping, form, request,
                response));
        } catch (Exception e) {
            throw new ServletException(e);
        }
    }

    /**
     * <p>Process a forward requested by this mapping (if any). Return
     * <code>true</code> if standard processing should continue, or
     * <code>false</code> if we have already handled this request.</p>
     *
     * @param request  The servlet request we are processing
     * @param response The servlet response we are creating
     * @param mapping  The ActionMapping we are using
     * @return <code>true</code> to continue normal processing;
     *         <code>false</code> if a response has been created.
     * @throws IOException      if an input/output error occurs
     * @throws ServletException if a servlet exception occurs
     */
    protected boolean processForward(HttpServletRequest request,
        HttpServletResponse response, ActionMapping mapping)
        throws IOException, ServletException {
        // Are we going to processing this request?
        String forward = mapping.getForward();

        if (forward == null) {
            return (true);
        }

        // If the forward can be unaliased into an action, then use the path of the action
        String actionIdPath = RequestUtils.actionIdURL(forward, this.moduleConfig, this.servlet);
        if (actionIdPath != null) {
            forward = actionIdPath;
        }

        internalModuleRelativeForward(forward, request, response);

        return (false);
    }

    /**
     * <p>Process an include requested by this mapping (if any). Return
     * <code>true</code> if standard processing should continue, or
     * <code>false</code> if we have already handled this request.</p>
     *
     * @param request  The servlet request we are processing
     * @param response The servlet response we are creating
     * @param mapping  The ActionMapping we are using
     * @return <code>true</code> to continue normal processing;
     *         <code>false</code> if a response has been created.
     * @throws IOException      if an input/output error occurs
     * @throws ServletException if thrown by invoked methods
     */
    protected boolean processInclude(HttpServletRequest request,
        HttpServletResponse response, ActionMapping mapping)
        throws IOException, ServletException {
        // Are we going to processing this request?
        String include = mapping.getInclude();

        if (include == null) {
            return (true);
        }

        // If the forward can be unaliased into an action, then use the path of the action
        String actionIdPath = RequestUtils.actionIdURL(include, this.moduleConfig, this.servlet);
        if (actionIdPath != null) {
            include = actionIdPath;
        }

        internalModuleRelativeInclude(include, request, response);

        return (false);
    }

    /**
     * <p>Automatically select a <code>Locale</code> for the current user, if
     * requested. <strong>NOTE</strong> - configuring Locale selection will
     * trigger the creation of a new <code>HttpSession</code> if
     * necessary.</p>
     *
     * @param request  The servlet request we are processing
     * @param response The servlet response we are creating
     */
    protected void processLocale(HttpServletRequest request,
        HttpServletResponse response) {
        // Are we configured to select the Locale automatically?
        if (!moduleConfig.getControllerConfig().getLocale()) {
            return;
        }

        // Has a Locale already been selected?
        HttpSession session = request.getSession();

        if (session.getAttribute(Globals.LOCALE_KEY) != null) {
            return;
        }

        // Use the Locale returned by the servlet container (if any)
        Locale locale = request.getLocale();

        if (locale != null) {
            if (log.isDebugEnabled()) {
                log.debug(" Setting user locale '" + locale + "'");
            }

            session.setAttribute(Globals.LOCALE_KEY, locale);
        }
    }

    /**
     * <p>Select the mapping used to process the selection path for this
     * request. If no mapping can be identified, create an error response and
     * return <code>null</code>.</p>
     *
     * @param request  The servlet request we are processing
     * @param response The servlet response we are creating
     * @param path     The portion of the request URI for selecting a mapping
     * @return The mapping used to process the selection path for this
     *         request.
     * @throws IOException if an input/output error occurs
     */
    protected ActionMapping processMapping(HttpServletRequest request,
        HttpServletResponse response, String path)
        throws IOException {
        // Is there a mapping for this path?
        ActionMapping mapping =
            (ActionMapping) moduleConfig.findActionConfig(path);

        // If a mapping is found, put it in the request and return it
        if (mapping != null) {
            request.setAttribute(Globals.MAPPING_KEY, mapping);

            return (mapping);
        }

        // Locate the mapping for unknown paths (if any)
        ActionConfig[] configs = moduleConfig.findActionConfigs();

        for (int i = 0; i < configs.length; i++) {
            if (configs[i].getUnknown()) {
                mapping = (ActionMapping) configs[i];
                request.setAttribute(Globals.MAPPING_KEY, mapping);

                return (mapping);
            }
        }

        // No mapping can be found to process this request
        String msg = getInternal().getMessage("processInvalid");

        log.error(msg + " " + path);
        response.sendError(HttpServletResponse.SC_NOT_FOUND, msg);

        return null;
    }

    /**
     * <p>If this is a multipart request, wrap it with a special wrapper.
     * Otherwise, return the request unchanged.</p>
     *
     * @param request The HttpServletRequest we are processing
     * @return A wrapped request, if the request is multipart; otherwise the
     *         original request.
     */
    protected HttpServletRequest processMultipart(HttpServletRequest request) {
        if (!"POST".equalsIgnoreCase(request.getMethod())) {
            return (request);
        }

        String contentType = request.getContentType();

        if ((contentType != null)
            && contentType.startsWith("multipart/form-data")) {
            return (new MultipartRequestWrapper(request));
        } else {
            return (request);
        }
    }

    /**
     * <p>Set the no-cache headers for all responses, if requested.
     * <strong>NOTE</strong> - This header will be overridden automatically if
     * a <code>RequestDispatcher.forward</code> call is ultimately
     * invoked.</p>
     *
     * @param request  The servlet request we are processing
     * @param response The servlet response we are creating
     */
    protected void processNoCache(HttpServletRequest request,
        HttpServletResponse response) {
        if (moduleConfig.getControllerConfig().getNocache()) {
            response.setHeader("Pragma", "No-cache");
            response.setHeader("Cache-Control", "no-cache,no-store,max-age=0");
            response.setDateHeader("Expires", 1);
        }
    }

    /**
     * <p>Identify and return the path component (from the request URI) that
     * we will use to select an <code>ActionMapping</code> with which to
     * dispatch. If no such path can be identified, create an error response
     * and return <code>null</code>.</p>
     *
     * @param request  The servlet request we are processing
     * @param response The servlet response we are creating
     * @return The path that will be used to select an action mapping.
     * @throws IOException if an input/output error occurs
     */
    protected String processPath(HttpServletRequest request,
        HttpServletResponse response)
        throws IOException {
        String path;

        // For prefix matching, match on the path info (if any)
        path = (String) request.getAttribute(INCLUDE_PATH_INFO);

        if (path == null) {
            path = request.getPathInfo();
        }

        if ((path != null) && (path.length() > 0)) {
            return (path);
        }