Java tutorial
/* * (C) Copyright 2006-2007 Nuxeo SA (http://nuxeo.com/) and others. * * 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. * * Contributors: * Nuxeo - initial API and implementation * * $Id: StaticNavigationHandler.java 21462 2007-06-26 21:16:36Z sfermigier $ */ package org.nuxeo.ecm.platform.ui.web.rest; import java.io.InputStream; import java.util.HashMap; import java.util.List; import java.util.Set; import javax.faces.FactoryFinder; import javax.faces.application.NavigationCase; import javax.faces.context.FacesContext; import javax.faces.context.FacesContextFactory; import javax.faces.lifecycle.Lifecycle; import javax.faces.lifecycle.LifecycleFactory; import javax.servlet.ServletContext; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.dom4j.DocumentException; import org.dom4j.Element; import org.dom4j.io.SAXReader; import org.jboss.seam.util.DTDEntityResolver; import org.nuxeo.runtime.api.Framework; import com.sun.faces.application.ApplicationAssociate; /** * View id helper that matches view ids and outcomes thanks to navigation cases defined in a faces-config.xml file. * <p> * Also handle some hot reload cases, by parsing the main faces-config.xml file. */ public class StaticNavigationHandler { private static final Log log = LogFactory.getLog(StaticNavigationHandler.class); private final HashMap<String, String> outcomeToViewId = new HashMap<String, String>(); private final HashMap<String, String> viewIdToOutcome = new HashMap<String, String>(); public StaticNavigationHandler(ServletContext context, HttpServletRequest request, HttpServletResponse response) { boolean created = false; FacesContext faces = FacesContext.getCurrentInstance(); if (faces == null) { // Acquire the FacesContext instance for this request FacesContextFactory facesContextFactory = (FacesContextFactory) FactoryFinder .getFactory(FactoryFinder.FACES_CONTEXT_FACTORY); LifecycleFactory lifecycleFactory = (LifecycleFactory) FactoryFinder .getFactory(FactoryFinder.LIFECYCLE_FACTORY); // force using default lifecycle instead of performing lookup on // conf Lifecycle lifecycle = lifecycleFactory.getLifecycle(LifecycleFactory.DEFAULT_LIFECYCLE); faces = facesContextFactory.getFacesContext(context, request, response, lifecycle); created = true; } try { ApplicationAssociate associate = ApplicationAssociate.getCurrentInstance(); for (Set<NavigationCase> cases : associate.getNavigationCaseListMappings().values()) { for (NavigationCase cnc : cases) { String toViewId = cnc.getToViewId(faces); String fromOutcome = cnc.getFromOutcome(); outcomeToViewId.put(fromOutcome, toViewId); viewIdToOutcome.put(toViewId, fromOutcome); } } if (Framework.isDevModeSet()) { handleHotReloadResources(context); } } finally { if (created) { faces.release(); } } } public String getOutcomeFromViewId(String viewId) { if (viewId == null) { return null; } viewId = viewId.replace(".faces", ".xhtml"); if (viewIdToOutcome.containsKey(viewId)) { return viewIdToOutcome.get(viewId); } return viewId; } public String getViewIdFromOutcome(String outcome) { if (outcome == null) { return null; } if (outcomeToViewId.containsKey(outcome)) { return outcomeToViewId.get(outcome).replace(".xhtml", ".faces"); } // try to guess the view name String viewId = "/" + outcome + ".faces"; log.warn("Guessing view id for outcome '" + outcome + "': use '" + viewId + "'"); return viewId; } /** * XXX hack: add manual parsing of the main faces-config.xml file navigation cases, to handle hot reload and work * around the JSF application cache. * <p> * TODO: try to reset and rebuild the app navigation cases by reflection, if it works... * * @since 5.6 */ protected void handleHotReloadResources(ServletContext context) { InputStream stream = null; if (context != null) { stream = context.getResourceAsStream("/WEB-INF/faces-config.xml"); } if (stream != null) { parse(stream); } } /** * @since 5.6 */ @SuppressWarnings("unchecked") protected void parse(InputStream stream) { Element root = getDocumentRoot(stream); List<Element> elements = root.elements("navigation-rule"); for (Element rule : elements) { List<Element> nav_cases = rule.elements("navigation-case"); for (Element nav_case : nav_cases) { Element from_el = nav_case.element("from-outcome"); Element to_el = nav_case.element("to-view-id"); if ((from_el != null) && (to_el != null)) { String from = from_el.getTextTrim(); String to = to_el.getTextTrim(); outcomeToViewId.put(from, to); viewIdToOutcome.put(to, from); } } } } /** * Gets the root element of the document. * * @since 5.6 */ protected static Element getDocumentRoot(InputStream stream) { try { SAXReader saxReader = new SAXReader(); saxReader.setEntityResolver(new DTDEntityResolver()); saxReader.setMergeAdjacentText(true); return saxReader.read(stream).getRootElement(); } catch (DocumentException de) { throw new RuntimeException(de); } } }