actionservlet.java

struts的源代码

     * <p>Process an HTTP "GET" request.</p>
     *
     * @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 exception occurs
     */
    public void doGet(HttpServletRequest request,
              HttpServletResponse response)
        throws IOException, ServletException {

        process(request, response);

    }


    /**
     * <p>Process an HTTP "POST" request.</p>
     *
     * @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 exception occurs
     */
    public void doPost(HttpServletRequest request,
               HttpServletResponse response)
        throws IOException, ServletException {

        process(request, response);

    }


    // --------------------------------------------------------- Public Methods


    /**
     * <p>Remember a servlet mapping from our web application deployment
     * descriptor, if it is for this servlet.</p>
     *
     * @param servletName The name of the servlet being mapped
     * @param urlPattern The URL pattern to which this servlet is mapped
     */
    public void addServletMapping(String servletName, String urlPattern) {

        if (log.isDebugEnabled()) {
            log.debug("Process servletName=" + servletName +
                      ", urlPattern=" + urlPattern);
        }
        if (servletName == null) {
            return;
        }
        if (servletName.equals(this.servletName)) {
            this.servletMapping = urlPattern;
        }

    }


    /**
     * <p>Return the <code>MessageResources</code> instance containing our
     * internal message strings.</p>
     *
     * @since Struts 1.1
     */
    public MessageResources getInternal() {

        return (this.internal);

    }


    // ------------------------------------------------------ Protected Methods

    /**
     * <p>Gracefully terminate use of any modules associated with this
     * application (if any).</p>
     *
     * @since Struts 1.1
     */
    protected void destroyModules() {

        ArrayList values = new ArrayList();
        Enumeration names = getServletContext().getAttributeNames();
        while (names.hasMoreElements()) {
            values.add(names.nextElement());
        }

        Iterator keys = values.iterator();
        while (keys.hasNext()) {
            String name = (String) keys.next();
            Object value = getServletContext().getAttribute(name);

            if (!(value instanceof ModuleConfig)) {
                continue;
            }

            ModuleConfig config = (ModuleConfig) value;

            if (this.getProcessorForModule(config) != null) {
                this.getProcessorForModule(config).destroy();
            }

            getServletContext().removeAttribute(name);

            PlugIn plugIns[] =
                (PlugIn[]) getServletContext().getAttribute(
                    Globals.PLUG_INS_KEY + config.getPrefix());

            if (plugIns != null) {
                for (int i = 0; i < plugIns.length; i++) {
                    int j = plugIns.length - (i + 1);
                    plugIns[j].destroy();
                }

                getServletContext().removeAttribute(
                    Globals.PLUG_INS_KEY + config.getPrefix());
            }

        }

    }


    /**
     * <p>Gracefully release any configDigester instance that we have created.</p>
     *
     * @since Struts 1.1
     */
    protected void destroyConfigDigester() {

        configDigester = null;

    }


    /**
     * <p>Gracefully terminate use of the internal MessageResources.</p>
     */
    protected void destroyInternal() {

        internal = null;

    }

    /**
     * <p>Return the module configuration object for the currently selected
     * module.</p>
     *
     * @param request The servlet request we are processing
     * @since Struts 1.1
     */
    protected ModuleConfig getModuleConfig
        (HttpServletRequest request) {

        ModuleConfig config = (ModuleConfig)
            request.getAttribute(Globals.MODULE_KEY);
        if (config == null) {
            config = (ModuleConfig)
                getServletContext().getAttribute(Globals.MODULE_KEY);
        }
        return (config);

    }


    /**
     * <p>Look up and return the {@link RequestProcessor} responsible for the
     * specified module, creating a new one if necessary.</p>
     *
     * @param config The module configuration for which to
     *  acquire and return a RequestProcessor.
     *
     * @exception ServletException if we cannot instantiate a RequestProcessor
     *  instance
     * @since Struts 1.1
     */
    protected synchronized RequestProcessor getRequestProcessor(ModuleConfig config)
        throws ServletException {

        // :FIXME: Document UnavailableException?

        RequestProcessor processor = this.getProcessorForModule(config);

        if (processor == null) {
            try {
                processor =
                    (RequestProcessor) RequestUtils.applicationInstance(
                        config.getControllerConfig().getProcessorClass());

            } catch (Exception e) {
                throw new UnavailableException(
                    "Cannot initialize RequestProcessor of class "
                        + config.getControllerConfig().getProcessorClass()
                        + ": "
                        + e);
            }

            processor.init(this, config);

            String key = Globals.REQUEST_PROCESSOR_KEY + config.getPrefix();
            getServletContext().setAttribute(key, processor);

        }

        return (processor);

    }


    /**
     * <p>Returns the RequestProcessor for the given module or null if one does not
     * exist.  This method will not create a RequestProcessor.</p>
     *
     * @param config The ModuleConfig.
     */
    private RequestProcessor getProcessorForModule(ModuleConfig config) {
        String key = Globals.REQUEST_PROCESSOR_KEY + config.getPrefix();
        return (RequestProcessor) getServletContext().getAttribute(key);
    }


    /**
     * <p>Initialize the factory used to create the module configuration.</p>
     * @since Struts 1.2
     */
    protected void initModuleConfigFactory(){
        String configFactory = getServletConfig().getInitParameter("configFactory");
        if (configFactory != null) {
            ModuleConfigFactory.setFactoryClass(configFactory);
        }
    }


    /**
     * <p>Initialize the module configuration information for the
     * specified module.</p>
     *
     * @param prefix Module prefix for this module
     * @param paths Comma-separated list of context-relative resource path(s)
     *  for this modules's configuration resource(s)
     *
     * @exception ServletException if initialization cannot be performed
     * @since Struts 1.1
     */
    protected ModuleConfig initModuleConfig(String prefix, String paths)
        throws ServletException {

        // :FIXME: Document UnavailableException? (Doesn't actually throw anything)

        if (log.isDebugEnabled()) {
            log.debug(
                "Initializing module path '"
                    + prefix
                    + "' configuration from '"
                    + paths
                    + "'");
        }

        // Parse the configuration for this module
        ModuleConfigFactory factoryObject = ModuleConfigFactory.createFactory();
        ModuleConfig config = factoryObject.createModuleConfig(prefix);

        // Configure the Digester instance we will use
        Digester digester = initConfigDigester();

        // Process each specified resource path
        while (paths.length() > 0) {
            digester.push(config);
            String path = null;
            int comma = paths.indexOf(',');
            if (comma >= 0) {
                path = paths.substring(0, comma).trim();
                paths = paths.substring(comma + 1);
            } else {
                path = paths.trim();
                paths = "";
            }

            if (path.length() < 1) {
                break;
            }

            this.parseModuleConfigFile(digester, path);
        }

        getServletContext().setAttribute(
            Globals.MODULE_KEY + config.getPrefix(),
            config);

        // Force creation and registration of DynaActionFormClass instances
        // for all dynamic form beans we wil be using
        FormBeanConfig fbs[] = config.findFormBeanConfigs();
        for (int i = 0; i < fbs.length; i++) {
            if (fbs[i].getDynamic()) {
                fbs[i].getDynaActionFormClass();
            }
        }

        return config;
    }


    /**
     * <p>Parses one module config file.</p>
     *
     * @param digester Digester instance that does the parsing
     * @param path The path to the config file to parse.
     *
     * @throws UnavailableException if file cannot be read or parsed
     * @since Struts 1.2
     */
    protected void parseModuleConfigFile(Digester digester, String path)
        throws UnavailableException {

        InputStream input = null;
        try {
            URL url = getServletContext().getResource(path);

            // If the config isn't in the servlet context, try the class loader
            // which allows the config files to be stored in a jar
            if (url == null) {
                url = getClass().getResource(path);
            }
            
            if (url == null) {
                String msg = internal.getMessage("configMissing", path);
                log.error(msg);
                throw new UnavailableException(msg);
            }
	    
            InputSource is = new InputSource(url.toExternalForm());
            input = url.openStream();
            is.setByteStream(input);
            digester.parse(is);

        } catch (MalformedURLException e) {
            handleConfigException(path, e);
        } catch (IOException e) {
            handleConfigException(path, e);
        } catch (SAXException e) {
            handleConfigException(path, e);
        } finally {
            if (input != null) {
                try {
                    input.close();
                } catch (IOException e) {
                    throw new UnavailableException(e.getMessage());
                }
            }
        }
    }


    /**
     * <p>Simplifies exception handling in the <code>parseModuleConfigFile</code> method.<p>
     * @param path
     * @param e
     * @throws UnavailableException as a wrapper around Exception
     */
    private void handleConfigException(String path, Exception e)
        throws UnavailableException {

        String msg = internal.getMessage("configParse", path);
        log.error(msg, e);
        throw new UnavailableException(msg);
    }


    /**
     * <p>Initialize the data sources for the specified module.</p>
     *
     * @param config ModuleConfig information for this module
     *
     * @exception ServletException if initialization cannot be performed
     * @since Struts 1.1
     */
    protected void initModuleDataSources(ModuleConfig config) throws ServletException {

        // :FIXME: Document UnavailableException?

        if (log.isDebugEnabled()) {
            log.debug("Initializing module path '" + config.getPrefix() +
                "' data sources");
        }

        ServletContextWriter scw =
            new ServletContextWriter(getServletContext());
        DataSourceConfig dscs[] = config.findDataSourceConfigs();
        if (dscs == null) {
            dscs = new DataSourceConfig[0];
        }

        dataSources.setFast(false);
        for (int i = 0; i < dscs.length; i++) {
            if (log.isDebugEnabled()) {
                log.debug("Initializing module path '" + config.getPrefix() +
                    "' data source '" + dscs[i].getKey() + "'");
            }