extensionvalidator.java

业界著名的tomcat服务器的最新6.0的源代码。

                                       ManifestResource.SYSTEM);
            containerManifestResources.add(mre);
        }
    }


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


    /**
     * Validates a <code>ArrayList</code> of <code>ManifestResource</code> 
     * objects. This method requires an application name (which is the 
     * context root of the application at runtime).  
     *
     * <code>false</false> is returned if the extension dependencies
     * represented by any given <code>ManifestResource</code> objects 
     * is not met.
     *
     * This method should also provide static validation of a Web Applicaiton 
     * if provided with the necessary parameters.
     *
     * @param appName The name of the Application that will appear in the 
     *                error messages
     * @param resources A list of <code>ManifestResource</code> objects 
     *                  to be validated.
     *
     * @return true if manifest resource file requirements are met
     */
    private static boolean validateManifestResources(String appName, 
                                                     ArrayList resources) {
        boolean passes = true;
        int failureCount = 0;        
        ArrayList availableExtensions = null;

        Iterator it = resources.iterator();
        while (it.hasNext()) {
            ManifestResource mre = (ManifestResource)it.next();
            ArrayList requiredList = mre.getRequiredExtensions();
            if (requiredList == null) {
                continue;
            }

            // build the list of available extensions if necessary
            if (availableExtensions == null) {
                availableExtensions = buildAvailableExtensionsList(resources);
            }

            // load the container level resource map if it has not been built
            // yet
            if (containerAvailableExtensions == null) {
                containerAvailableExtensions
                    = buildAvailableExtensionsList(containerManifestResources);
            }

            // iterate through the list of required extensions
            Iterator rit = requiredList.iterator();
            while (rit.hasNext()) {
                boolean found = false;
                Extension requiredExt = (Extension)rit.next();
                // check the applicaion itself for the extension
                if (availableExtensions != null) {
                    Iterator ait = availableExtensions.iterator();
                    while (ait.hasNext()) {
                        Extension targetExt = (Extension) ait.next();
                        if (targetExt.isCompatibleWith(requiredExt)) {
                            requiredExt.setFulfilled(true);
                            found = true;
                            break;
                        }
                    }
                }
                // check the container level list for the extension
                if (!found && containerAvailableExtensions != null) {
                    Iterator cit = containerAvailableExtensions.iterator();
                    while (cit.hasNext()) {
                        Extension targetExt = (Extension) cit.next();
                        if (targetExt.isCompatibleWith(requiredExt)) {
                            requiredExt.setFulfilled(true);
                            found = true;
                            break;
                        }
                    }
                }
                if (!found) {
                    // Failure
                    log.info(sm.getString(
                        "extensionValidator.extension-not-found-error",
                        appName, mre.getResourceName(),
                        requiredExt.getExtensionName()));
                    passes = false;
                    failureCount++;
                }
            }
        }

        if (!passes) {
            log.info(sm.getString(
                     "extensionValidator.extension-validation-error", appName,
                     failureCount + ""));
        }

        return passes;
    }
    
   /* 
    * Build this list of available extensions so that we do not have to 
    * re-build this list every time we iterate through the list of required 
    * extensions. All available extensions in all of the 
    * <code>MainfestResource</code> objects will be added to a 
    * <code>HashMap</code> which is returned on the first dependency list
    * processing pass. 
    *
    * The key is the name + implementation version.
    *
    * NOTE: A list is built only if there is a dependency that needs 
    * to be checked (performance optimization).
    *
    * @param resources A list of <code>ManifestResource</code> objects
    *
    * @return HashMap Map of available extensions
    */
    private static ArrayList buildAvailableExtensionsList(ArrayList resources) {

        ArrayList availableList = null;

        Iterator it = resources.iterator();
        while (it.hasNext()) {
            ManifestResource mre = (ManifestResource)it.next();
            ArrayList list = mre.getAvailableExtensions();
            if (list != null) {
                Iterator values = list.iterator();
                while (values.hasNext()) {
                    Extension ext = (Extension) values.next();
                    if (availableList == null) {
                        availableList = new ArrayList();
                        availableList.add(ext);
                    } else {
                        availableList.add(ext);
                    }
                }
            }
        }

        return availableList;
    }
    
    /**
     * Return the Manifest from a jar file or war file
     *
     * @param inStream Input stream to a WAR or JAR file
     * @return The WAR's or JAR's manifest
     */
    private static Manifest getManifest(InputStream inStream)
            throws IOException {

        Manifest manifest = null;
        JarInputStream jin = null;

        try {
            jin = new JarInputStream(inStream);
            manifest = jin.getManifest();
            jin.close();
            jin = null;
        } finally {
            if (jin != null) {
                try {
                    jin.close();
                } catch (Throwable t) {
                    // Ignore
                }
            }
        }

        return manifest;
    }


    /**
     * Add the JARs specified to the extension list.
     */
    private static void addFolderList(String property) {

        // get the files in the extensions directory
        String extensionsDir = System.getProperty(property);
        if (extensionsDir != null) {
            StringTokenizer extensionsTok
                = new StringTokenizer(extensionsDir, File.pathSeparator);
            while (extensionsTok.hasMoreTokens()) {
                File targetDir = new File(extensionsTok.nextToken());
                if (!targetDir.exists() || !targetDir.isDirectory()) {
                    continue;
                }
                File[] files = targetDir.listFiles();
                for (int i = 0; i < files.length; i++) {
                    if (files[i].getName().toLowerCase().endsWith(".jar")) {
                        try {
                            addSystemResource(files[i]);
                        } catch (IOException e) {
                            log.error
                                (sm.getString
                                 ("extensionValidator.failload", files[i]), e);
                        }
                    }
                }
            }
        }

    }


}