public synchronized void initialize()

in velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/ResourceManagerImpl.java [96:206]
78 lines of code
11 McCabe index (conditional complexity)

    public synchronized void initialize(final RuntimeServices rs)
    {
        if (isInit)
        {
            log.debug("Re-initialization of ResourceLoader attempted and ignored.");
            return;
        }

        ResourceLoader resourceLoader = null;

        rsvc = rs;
        log = rsvc.getLog("loader");

        log.trace("ResourceManager initializing: {}", this.getClass());

        assembleResourceLoaderInitializers();

        for (ExtProperties configuration : sourceInitializerList)
        {
            /*
             * Resource loader can be loaded either via class name or be passed
             * in as an instance.
             */

            String loaderClass = StringUtils.trim(configuration.getString(RuntimeConstants.RESOURCE_LOADER_CLASS));
            ResourceLoader loaderInstance = (ResourceLoader) configuration.get(RuntimeConstants.RESOURCE_LOADER_INSTANCE);

            if (loaderInstance != null)
            {
                resourceLoader = loaderInstance;
            } else if (loaderClass != null)
            {
                resourceLoader = ResourceLoaderFactory.getLoader(rsvc, loaderClass);
            } else
            {
                String msg = "Unable to find 'resource.loader." +
                    configuration.getString(RuntimeConstants.RESOURCE_LOADER_IDENTIFIER) +
                    ".class' specification in configuration." +
                    " This is a critical value.  Please adjust configuration.";
                log.error(msg);
                throw new VelocityException(msg, null, rsvc.getLogContext().getStackTrace());
            }

            resourceLoader.commonInit(rsvc, configuration);
            resourceLoader.init(configuration);
            resourceLoaders.add(resourceLoader);
        }

        /*
         * now see if this is overridden by configuration
         */

        logWhenFound = rsvc.getBoolean(RuntimeConstants.RESOURCE_MANAGER_LOGWHENFOUND, true);

        /*
         *  now, is a global cache specified?
         */

        String cacheClassName = rsvc.getString(RuntimeConstants.RESOURCE_MANAGER_CACHE_CLASS);

        Object cacheObject = null;

        if (StringUtils.isNotEmpty(cacheClassName))
        {
            try
            {
                cacheObject = ClassUtils.getNewInstance(cacheClassName);
            }
            catch (ClassNotFoundException cnfe)
            {
                String msg = "The specified class for ResourceCache (" + cacheClassName +
                          ") does not exist or is not accessible to the current classloader.";
                log.error(msg, cnfe);
                throw new VelocityException(msg, cnfe);
            }
            catch (IllegalAccessException ae)
            {
                throw new VelocityException("Could not access class '"
                    + cacheClassName + "'", ae);
            }
            catch (InstantiationException ie)
            {
                throw new VelocityException("Could not instantiate class '"
                    + cacheClassName + "'", ie);
            }

            if (!(cacheObject instanceof ResourceCache))
            {
                String msg = "The specified resource cache class (" + cacheClassName +
                          ") must implement " + ResourceCache.class.getName();
                log.error(msg);
                throw new RuntimeException(msg);
            }
        }

        /*
         *  if we didn't get through that, just use the default.
         */
        if (cacheObject == null)
        {
            cacheObject = new ResourceCacheImpl();
        }

        globalCache = (ResourceCache) cacheObject;

        globalCache.initialize(rsvc);

        isInit = true;

        log.trace("Default ResourceManager initialization complete.");
    }