Java tutorial
/* * Copyright 2011 cruxframework.org. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package org.cruxframework.crux.core.declarativeui.template; import java.net.URL; import java.util.ArrayList; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.cruxframework.crux.core.config.ConfigurationFactory; import org.cruxframework.crux.core.declarativeui.hotdeploy.HotDeploymentScanner; import org.cruxframework.crux.core.server.Environment; import org.cruxframework.crux.core.utils.URLUtils; import org.cruxframework.crux.scanner.Scanners; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.w3c.dom.Text; /** * * @author Thiago da Rosa de Bustamante * */ public class Templates { private static boolean hotDeploymentScannerStarted = false; private static final Log logger = LogFactory.getLog(Templates.class); private static Map<String, Set<String>> registeredLibraries = new HashMap<String, Set<String>>(); private static boolean starting = false; private static Map<String, Document> templates = new HashMap<String, Document>(); private static Map<String, Set<String>> widgetTemplates = new HashMap<String, Set<String>>(); private static Map<String, URL> foundTemplates = new HashMap<String, URL>(); private static boolean initialized = false; /** * * @return */ public static Set<String> getRegisteredLibraries() { if (!initialized) { initialize(); } return registeredLibraries.keySet(); } /** * * @param library * @return */ public static Set<String> getRegisteredLibraryWidgetTemplates(String library) { if (!initialized) { initialize(); } return widgetTemplates.get(library); } /** * * @param library * @return */ public static Set<String> getRegisteredLibraryTemplates(String library) { if (!initialized) { initialize(); } return registeredLibraries.get(library); } /** * * @param library * @param id * @return */ public static Document getTemplate(String library, String id) { return getTemplate(library, id, false); } /** * * @param library * @param id * @return */ public static Document getTemplate(String library, String id, boolean clone) { if (!initialized) { initialize(); } Document document = templates.get(library + "_" + id); if (document != null) { document = (Document) document.cloneNode(true); } return document; } /** * */ public static synchronized void initialize() { if (initialized) { return; } starting = true; templates.clear(); widgetTemplates.clear(); registeredLibraries.clear(); foundTemplates.clear(); Scanners.resetScanner(TemplatesScanner.class); logger.info("Searching for template files."); TemplatesScanner.getInstance().scanArchives(); initializeWidgetTemplates(); setInitialized(); } /** * */ public static void restart() { initialized = false; initialize(); } /** * */ public static void reset() { initialized = false; templates.clear(); widgetTemplates.clear(); registeredLibraries.clear(); foundTemplates.clear(); } static void setInitialized() { if (!hotDeploymentScannerStarted) { hotDeploymentScannerStarted = true; if (!Environment.isProduction() && Boolean .parseBoolean(ConfigurationFactory.getConfigurations().enableHotDeploymentForWebDirs())) { HotDeploymentScanner.scanWebDirs(); } } starting = false; initialized = true; } /** * @param parentElement * @return */ static List<Element> extractChildrenElements(Element parentElement) { List<Element> result = new ArrayList<Element>(); NodeList childNodes = parentElement.getChildNodes(); for (int i = 0; i < childNodes.getLength(); i++) { Node node = childNodes.item(i); switch (node.getNodeType()) { case Node.COMMENT_NODE: //ignore node break; case Node.TEXT_NODE: Text textNode = (Text) node; if (textNode.getWholeText().trim().length() > 0) { return null; } break; case Node.ELEMENT_NODE: result.add((Element) node); break; default: return null; } } return result; } /** * @return */ public static boolean isStarting() { return starting; } /** * @param template * @return */ static boolean isWidgetTemplate(Document template) { boolean isWidget = false; if (template != null) { Element templateElement = template.getDocumentElement(); List<Element> children = extractChildrenElements(templateElement); if (children != null && children.size() == 1) { Element element = children.get(0); String namespaceURI = element.getNamespaceURI(); if (namespaceURI != null) { if (namespaceURI.startsWith("http://www.cruxframework.org/crux/")) { isWidget = true; } else if (namespaceURI.startsWith("http://www.cruxframework.org/templates/")) { String library = namespaceURI.substring("http://www.cruxframework.org/templates/".length()); Document refTemplate = getTemplate(library, element.getLocalName()); isWidget = isWidgetTemplate(refTemplate); } } } } return isWidget; } /** * * @param templateId * @param template */ static void registerTemplate(String templateId, Document template, URL templateURL) { Element templateElement = template.getDocumentElement(); String library = templateElement.getAttribute("library"); String key = library + "_" + templateId; if (templates.containsKey(key)) { URL registeredURL = foundTemplates.get(key); if (!URLUtils.isIdenticResource(templateURL, registeredURL, templateId + ".template.xml")) { throw new TemplateException( "Duplicated template found. Library: [" + library + "]. Template: [" + templateId + "]."); } } if (!registeredLibraries.containsKey(library)) { registeredLibraries.put(library, new HashSet<String>()); } registeredLibraries.get(library).add(templateId); templates.put(key, template); foundTemplates.put(key, templateURL); } /** * */ private static void initializeWidgetTemplates() { for (Entry<String, Document> entry : templates.entrySet()) { if (isWidgetTemplate(entry.getValue())) { String templateKey = entry.getKey(); String[] templateIdParts = templateKey.split("_"); Set<String> templates = widgetTemplates.get(templateIdParts[0]); if (templates == null) { templates = new HashSet<String>(); widgetTemplates.put(templateIdParts[0], templates); } templates.add(templateIdParts[1]); } } } }