Java tutorial
/** * OLAT - Online Learning and Training<br> * http://www.olat.org * <p> * Licensed under the Apache License, Version 2.0 (the "License"); <br> * you may not use this file except in compliance with the License.<br> * You may obtain a copy of the License at * <p> * http://www.apache.org/licenses/LICENSE-2.0 * <p> * Unless required by applicable law or agreed to in writing,<br> * software distributed under the License is distributed on an "AS IS" BASIS, <br> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br> * See the License for the specific language governing permissions and <br> * limitations under the License. * <p> * Copyright (c) since 2004 at Multimedia- & E-Learning Services (MELS),<br> * University of Zurich, Switzerland. * <p> */ package org.olat.modules.scorm; import java.io.BufferedInputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.net.URLDecoder; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Map; import org.dom4j.Document; import org.dom4j.Element; import org.dom4j.XPath; import org.olat.core.gui.components.tree.GenericTreeModel; import org.olat.core.gui.components.tree.GenericTreeNode; import org.olat.core.gui.components.tree.TreeNode; import org.olat.core.logging.AssertException; import org.olat.core.logging.OLATRuntimeException; import org.olat.core.util.xml.XMLParser; import org.olat.ims.resources.IMSEntityResolver; /** * @author Felix Jost */ public class ScormCPManifestTreeModel extends GenericTreeModel { private Element rootElement; private final Map nsuris = new HashMap(2); private final Map hrefToTreeNode = new HashMap(); private Map resources; // keys: resource att 'identifier'; values: resource att 'href' private int nodeId = 0; // number tree ascending in depth first traversal. Keys: GenericTreeNode | values: int private final Map nodeToId = new HashMap(); private final Map scormIdToNode = new HashMap(); private final Map itemStatus; /** * Constructor of the content packaging tree model * * @param manifest the imsmanifest.xml file * @param itemStatus a Map containing the status of each item like "completed, not attempted, ..." */ public ScormCPManifestTreeModel(final File manifest, final Map itemStatus) { this.itemStatus = itemStatus; final Document doc = loadDocument(manifest); // get all organization elements. need to set namespace rootElement = doc.getRootElement(); final String nsuri = rootElement.getNamespace().getURI(); nsuris.put("ns", nsuri); final XPath meta = rootElement.createXPath("//ns:organization"); meta.setNamespaceURIs(nsuris); final XPath metares = rootElement.createXPath("//ns:resources"); metares.setNamespaceURIs(nsuris); final Element elResources = (Element) metares.selectSingleNode(rootElement); if (elResources == null) { throw new AssertException("could not find element resources"); } final List resourcesList = elResources.elements("resource"); resources = new HashMap(resourcesList.size()); for (final Iterator iter = resourcesList.iterator(); iter.hasNext();) { final Element elRes = (Element) iter.next(); final String identVal = elRes.attributeValue("identifier"); String hrefVal = elRes.attributeValue("href"); if (hrefVal != null) { // href is optional element for resource element try { hrefVal = URLDecoder.decode(hrefVal, "UTF-8"); } catch (final UnsupportedEncodingException e) { // each JVM must implement UTF-8 } } resources.put(identVal, hrefVal); } /* * Get all organizations */ List organizations = new LinkedList(); organizations = meta.selectNodes(rootElement); if (organizations.isEmpty()) { throw new AssertException("could not find element organization"); } final GenericTreeNode gtn = buildTreeNodes(organizations); setRootNode(gtn); rootElement = null; // help gc resources = null; } /** * @param href * @return TreeNode representing this href */ public TreeNode lookupTreeNodeByHref(final String href) { return (TreeNode) hrefToTreeNode.get(href); } private GenericTreeNode buildTreeNodes(final List organizations) { final GenericTreeNode gtn = new GenericTreeNode(); // 0 is a valid index since List is testet be be not empty above final String rootNode = ((Element) organizations.get(0)).getParent().elementText("default"); // if only one organization avoid too much hierarchy levels... if (organizations.size() == 1) { return buildNode((Element) organizations.get(0)); } // FIXME: localize "Content:" gtn.setTitle((rootNode == null) ? "Content:" : rootNode); gtn.setIconCssClass("o_scorm_org"); gtn.setAccessible(false); for (int i = 0; i < organizations.size(); ++i) { final GenericTreeNode gtnchild = buildNode((Element) organizations.get(i)); gtn.addChild(gtnchild); } return gtn; } private GenericTreeNode buildNode(final Element item) { final GenericTreeNode treeNode = new GenericTreeNode(); // extract title String title = item.elementText("title"); if (title == null) { title = item.attributeValue("identifier"); } treeNode.setAltText(title); treeNode.setTitle(title); if (item.getName().equals("organization")) { treeNode.setIconCssClass("o_scorm_org"); treeNode.setAccessible(false); } else if (item.getName().equals("item")) { scormIdToNode.put(new Integer(nodeId).toString(), treeNode); nodeToId.put(treeNode, new Integer(nodeId)); // set node images according to scorm sco status final String itemStatusDesc = (String) itemStatus.get(Integer.toString(nodeId)); treeNode.setIconCssClass("o_scorm_item"); if (itemStatusDesc != null) { // add icon decorator for current status treeNode.setIconDecorator1CssClass("o_scorm_" + itemStatusDesc); } nodeId++; // set resolved file path directly final String identifierref = item.attributeValue("identifierref"); final XPath meta = rootElement.createXPath("//ns:resource[@identifier='" + identifierref + "']"); meta.setNamespaceURIs(nsuris); final String href = (String) resources.get(identifierref); if (href != null) { treeNode.setUserObject(href); // allow lookup of a treenode given a href so we can quickly adjust the menu if the user clicks on hyperlinks within the text hrefToTreeNode.put(href, treeNode); } else { treeNode.setAccessible(false); } } final List chds = item.elements("item"); final int childcnt = chds.size(); for (int i = 0; i < childcnt; i++) { final Element childitem = (Element) chds.get(i); final GenericTreeNode gtnchild = buildNode(childitem); treeNode.addChild(gtnchild); } return treeNode; } private Document loadDocument(final File documentF) { FileInputStream in = null; BufferedInputStream bis = null; Document doc = null; try { in = new FileInputStream(documentF); bis = new BufferedInputStream(in); final XMLParser xmlParser = new XMLParser(new IMSEntityResolver()); doc = xmlParser.parse(bis, false); } catch (final IOException e) { throw new OLATRuntimeException(ScormCPManifestTreeModel.class, "could not read and parse from file " + documentF.getAbsolutePath(), e); } finally { try { if (in != null) { in.close(); } if (bis != null) { bis.close(); } } catch (final Exception e) { // we did our best to close the inputStream } } return doc; } /** * @param treeNode * @return int */ public int lookupScormNodeId(final TreeNode treeNode) { final Integer nodeInteger = (Integer) nodeToId.get(treeNode); return nodeInteger.intValue(); } /** * @param itemId * @return an uri that points to the ressource identified by a flat id */ public TreeNode getNodeByScormItemId(final String itemId) { final TreeNode node = (TreeNode) scormIdToNode.get(itemId); return node; } /** * @return a map with key->ascending flat string number from traversing tree. value->TreeNode */ public Map getScormIdToNodeRelation() { return scormIdToNode; } }