actionservlet.java

struts的源代码

            DataSource ds = null;
            try {
                ds = (DataSource)
                    RequestUtils.applicationInstance(dscs[i].getType());
                BeanUtils.populate(ds, dscs[i].getProperties());
                ds.setLogWriter(scw);

            } catch (Exception e) {
                log.error(internal.getMessage("dataSource.init", dscs[i].getKey()), e);
                throw new UnavailableException
                    (internal.getMessage("dataSource.init", dscs[i].getKey()));
            }
            getServletContext().setAttribute
                (dscs[i].getKey() + config.getPrefix(), ds);
            dataSources.put(dscs[i].getKey(), ds);
        }

        dataSources.setFast(true);

    }


    /**
     * <p>Initialize the plug ins 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 initModulePlugIns
        (ModuleConfig config) throws ServletException {

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

        PlugInConfig plugInConfigs[] = config.findPlugInConfigs();
        PlugIn plugIns[] = new PlugIn[plugInConfigs.length];

        getServletContext().setAttribute(Globals.PLUG_INS_KEY + config.getPrefix(), plugIns);
        for (int i = 0; i < plugIns.length; i++) {
            try {
                plugIns[i] =
                    (PlugIn)RequestUtils.applicationInstance(plugInConfigs[i].getClassName());
                 BeanUtils.populate(plugIns[i], plugInConfigs[i].getProperties());
                  // Pass the current plugIn config object to the PlugIn.
                  // The property is set only if the plugin declares it.
                  // This plugin config object is needed by Tiles
                try {
                    PropertyUtils.setProperty(
                        plugIns[i],
                        "currentPlugInConfigObject",
                        plugInConfigs[i]);
                } catch (Exception e) {
                  // FIXME Whenever we fail silently, we must document a valid reason
                  // for doing so.  Why should we fail silently if a property can't be set on
                  // the plugin?
                    /**
                     * Between version 1.138-1.140 cedric made these changes.
                     * The exceptions are caught to deal with containers applying strict security.
                     * This was in response to bug #15736
                     *
                     * Recommend that we make the currentPlugInConfigObject part of the PlugIn Interface if we can, Rob
                     */
                }
                plugIns[i].init(this, config);

            } catch (ServletException e) {
                throw e;
            } catch (Exception e) {
                String errMsg =
                    internal.getMessage(
                        "plugIn.init",
                        plugInConfigs[i].getClassName());

                log(errMsg, e);
                throw new UnavailableException(errMsg);
            }
        }

    }


    /**
     * <p>Initialize the application <code>MessageResources</code> 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 initModuleMessageResources(ModuleConfig config)
        throws ServletException {

        MessageResourcesConfig mrcs[] = config.findMessageResourcesConfigs();
        for (int i = 0; i < mrcs.length; i++) {
            if ((mrcs[i].getFactory() == null)
                || (mrcs[i].getParameter() == null)) {
                continue;
            }
            if (log.isDebugEnabled()) {
                log.debug(
                    "Initializing module path '"
                        + config.getPrefix()
                        + "' message resources from '"
                        + mrcs[i].getParameter()
                        + "'");
            }

            String factory = mrcs[i].getFactory();
            MessageResourcesFactory.setFactoryClass(factory);
            MessageResourcesFactory factoryObject =
                MessageResourcesFactory.createFactory();
            factoryObject.setConfig(mrcs[i]);

            MessageResources resources =
                factoryObject.createResources(mrcs[i].getParameter());
            resources.setReturnNull(mrcs[i].getNull());
            resources.setEscape(mrcs[i].isEscape());
            getServletContext().setAttribute(
                mrcs[i].getKey() + config.getPrefix(),
                resources);
        }

    }


    /**
     * <p>Create (if needed) and return a new <code>Digester</code>
     * instance that has been initialized to process Struts module
     * configuration files and configure a corresponding <code>ModuleConfig</code>
     * object (which must be pushed on to the evaluation stack before parsing
     * begins).</p>
     *
     * @exception ServletException if a Digester cannot be configured
     * @since Struts 1.1
     */
    protected Digester initConfigDigester() throws ServletException {

        // :FIXME: Where can ServletException be thrown?

        // Do we have an existing instance?
        if (configDigester != null) {
            return (configDigester);
        }

        // Create a new Digester instance with standard capabilities
        configDigester = new Digester();
        configDigester.setNamespaceAware(true);
        configDigester.setValidating(this.isValidating());
        configDigester.setUseContextClassLoader(true);
        configDigester.addRuleSet(new ConfigRuleSet());

        for (int i = 0; i < registrations.length; i += 2) {
            URL url = this.getClass().getResource(registrations[i+1]);
            if (url != null) {
                configDigester.register(registrations[i], url.toString());
            }
        }

        this.addRuleSets();

        // Return the completely configured Digester instance
        return (configDigester);
    }


    /**
     * <p>Add any custom RuleSet instances to configDigester that have
     * been specified in the <code>rulesets</code> init parameter.</p>
     *
     * @throws ServletException
     */
    private void addRuleSets() throws ServletException {

        String rulesets = getServletConfig().getInitParameter("rulesets");
        if (rulesets == null) {
            rulesets = "";
        }

        rulesets = rulesets.trim();
        String ruleset = null;
        while (rulesets.length() > 0) {
            int comma = rulesets.indexOf(",");
            if (comma < 0) {
                ruleset = rulesets.trim();
                rulesets = "";
            } else {
                ruleset = rulesets.substring(0, comma).trim();
                rulesets = rulesets.substring(comma + 1).trim();
            }

            if (log.isDebugEnabled()) {
                log.debug("Configuring custom Digester Ruleset of type " + ruleset);
            }

            try {
                RuleSet instance = (RuleSet) RequestUtils.applicationInstance(ruleset);
                this.configDigester.addRuleSet(instance);
            } catch (Exception e) {
                log.error("Exception configuring custom Digester RuleSet", e);
                throw new ServletException(e);
            }
        }
    }


    /**
     * <p>Check the status of the <code>validating</code> initialization parameter.</p>
     *
     * @return true if the module Digester should validate.
     */
    private boolean isValidating() {

        boolean validating = true;
        String value = getServletConfig().getInitParameter("validating");

        if ("false".equalsIgnoreCase(value)
            || "no".equalsIgnoreCase(value)
            || "n".equalsIgnoreCase(value)
            || "0".equalsIgnoreCase(value)) {

            validating = false;
        }

        return validating;
    }



    /**
     * <p>Initialize our internal MessageResources bundle.</p>
     *
     * @exception ServletException if we cannot initialize these resources
     */
    protected void initInternal() throws ServletException {

        // :FIXME: Document UnavailableException

        try {
            internal = MessageResources.getMessageResources(internalName);
        } catch (MissingResourceException e) {
            log.error("Cannot load internal resources from '" + internalName + "'",
                e);
            throw new UnavailableException
                ("Cannot load internal resources from '" + internalName + "'");
        }

    }


    /**
     * <p>Initialize other global characteristics of the controller servlet.</p>
     *
     * @exception ServletException if we cannot initialize these resources
     */
    protected void initOther() throws ServletException {

        String value = null;
        value = getServletConfig().getInitParameter("config");
        if (value != null) {
            config = value;
        }

        // Backwards compatibility for form beans of Java wrapper classes
        // Set to true for strict Struts 1.0 compatibility
        value = getServletConfig().getInitParameter("convertNull");
        if ("true".equalsIgnoreCase(value)
            || "yes".equalsIgnoreCase(value)
            || "on".equalsIgnoreCase(value)
            || "y".equalsIgnoreCase(value)
            || "1".equalsIgnoreCase(value)) {

            convertNull = true;
        }

        if (convertNull) {
            ConvertUtils.deregister();
            ConvertUtils.register(new BigDecimalConverter(null), BigDecimal.class);
            ConvertUtils.register(new BigIntegerConverter(null), BigInteger.class);
            ConvertUtils.register(new BooleanConverter(null), Boolean.class);
            ConvertUtils.register(new ByteConverter(null), Byte.class);
            ConvertUtils.register(new CharacterConverter(null), Character.class);
            ConvertUtils.register(new DoubleConverter(null), Double.class);
            ConvertUtils.register(new FloatConverter(null), Float.class);
            ConvertUtils.register(new IntegerConverter(null), Integer.class);
            ConvertUtils.register(new LongConverter(null), Long.class);
            ConvertUtils.register(new ShortConverter(null), Short.class);
        }

    }


    /**
     * <p>Initialize the servlet mapping under which our controller servlet
     * is being accessed.  This will be used in the <code>&html:form&gt;</code>
     * tag to generate correct destination URLs for form submissions.</p>
     *
     * @throws ServletException if error happens while scanning web.xml
     */
    protected void initServlet() throws ServletException {

        // Remember our servlet name
        this.servletName = getServletConfig().getServletName();

        // Prepare a Digester to scan the web application deployment descriptor
        Digester digester = new Digester();
        digester.push(this);
        digester.setNamespaceAware(true);
        digester.setValidating(false);

        // Register our local copy of the DTDs that we can find
        for (int i = 0; i < registrations.length; i += 2) {
            URL url = this.getClass().getResource(registrations[i+1]);
            if (url != null) {
                digester.register(registrations[i], url.toString());
            }
        }

        // Configure the processing rules that we need
        digester.addCallMethod("web-app/servlet-mapping",
                               "addServletMapping", 2);
        digester.addCallParam("web-app/servlet-mapping/servlet-name", 0);
        digester.addCallParam("web-app/servlet-mapping/url-pattern", 1);

        // Process the web application deployment descriptor
        if (log.isDebugEnabled()) {
            log.debug("Scanning web.xml for controller servlet mapping");
        }

        InputStream input =
            getServletContext().getResourceAsStream("/WEB-INF/web.xml");

        if (input == null) {
            log.error(internal.getMessage("configWebXml"));
            throw new ServletException(internal.getMessage("configWebXml"));
        }

        try {
            digester.parse(input);

        } catch (IOException e) {
            log.error(internal.getMessage("configWebXml"), e);
            throw new ServletException(e);

        } catch (SAXException e) {
            log.error(internal.getMessage("configWebXml"), e);
            throw new ServletException(e);

        } finally {
            try {
                input.close();
            } catch (IOException e) {
                log.error(internal.getMessage("configWebXml"), e);
                throw new ServletException(e);
            }
        }

        // Record a servlet context attribute (if appropriate)
        if (log.isDebugEnabled()) {
            log.debug("Mapping for servlet '" + servletName + "' = '" +
                servletMapping + "'");
        }

        if (servletMapping != null) {
            getServletContext().setAttribute(Globals.SERVLET_KEY, servletMapping);
        }

    }


    /**
     * <p>Perform the standard request processing for this request, and create
     * the corresponding response.</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 is thrown
     */
    protected void process(HttpServletRequest request, HttpServletResponse response)
        throws IOException, ServletException {

        ModuleUtils.getInstance().selectModule(request, getServletContext());
        ModuleConfig config = getModuleConfig(request);

        RequestProcessor processor = getProcessorForModule(config);
        if (processor == null) {
           processor = getRequestProcessor(config);
        }
        processor.process(request, response);

    }

}