Java tutorial
/* * Copyright (C) 2007 Unicon, Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this distribution. It is also available here: * http://www.fsf.org/licensing/licenses/gpl.html * * As a special exception to the terms and conditions of version * 2 of the GPL, you may redistribute this Program in connection * with Free/Libre and Open Source Software ("FLOSS") applications * as described in the GPL FLOSS exception. You should have received * a copy of the text describing the FLOSS exception along with this * distribution. */ package net.unicon.academus.apps.content; import net.unicon.academus.apps.XHTMLFilter; import net.unicon.academus.apps.XHTMLFilter.XHTMLFilterConfig; import net.unicon.demetrius.DemetriusException; import net.unicon.demetrius.IFile; import net.unicon.demetrius.IResourceFactory; import net.unicon.demetrius.fac.AbstractResourceFactory; import org.dom4j.Document; import org.dom4j.Element; import org.dom4j.Node; import org.dom4j.io.SAXReader; import org.xml.sax.InputSource; import java.io.*; import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.Map; public final class Web { // Static Members. private static final Map cache = Collections.synchronizedMap(new HashMap()); private static final String[][] replace = new String[][] { new String[] { """, """ }, new String[] { "<", "<" }, new String[] { ">", ">" }, new String[] { " ", " " }, new String[] { "©", "©" }, new String[] { "&", "&" } // MUST BE LAST!! }; // Instance Members. private final String dfltDoc; private final IResourceFactory fac; /* * Public API. */ public static Web fromUrl(String url) { // Assertions. if (url == null) { String msg = "Argument 'url' cannot be null."; throw new IllegalArgumentException(msg); } // Check the cache first. if (cache.containsKey(url)) { return (Web) cache.get(url); } Web rslt = null; synchronized (Web.class) { // Double-check. if (cache.containsKey(url)) { return (Web) cache.get(url); } /* We must obtain it from the url. * Layout of the Web URL is as follows: * * 0 Protocol (i.e. WEB:) * 1 [Empty... "//" after protocol] * 2 Class Name * 3 Default Document * 4+ Resource Factory */ String[] tokens = url.split("/", 5); // Default Document. String dfltDoc = tokens[3]; // Resouce Factory. String facUrl = tokens[4]; IResourceFactory fac; try { fac = AbstractResourceFactory.fromUrl(facUrl); rslt = new Web(dfltDoc, fac); // Add to the cache. cache.put(url, rslt); } catch (DemetriusException e) { throw new RuntimeException("Resource with the given url was not found. " + facUrl); } } return rslt; } public String getDefaultDocument() { return dfltDoc; } public class DocumentData { private Map attributes; private String body; private DocumentData(String body, Map attributes) { this.body = body; this.attributes = attributes; } public Map getAttributes() { return attributes; } public String getBody() { return body; } } public DocumentData getDocument(String path, String bodyXpath, String inputTags, XHTMLFilterConfig filterConfig) { // Assertions. if (path == null) { String msg = "Argument 'path' cannot be null."; throw new IllegalArgumentException(msg); } if (bodyXpath == null) { String msg = "Argument 'bodyXpath' cannot be null."; throw new IllegalArgumentException(msg); } if (inputTags == null) { String msg = "Argument 'inputTags' cannot be null."; throw new IllegalArgumentException(msg); } Map attrs = new HashMap(); StringBuffer body = new StringBuffer(); try { IFile f = (IFile) fac.getResource(path); Reader r = new BufferedReader(new InputStreamReader(f.getInputStream())); String xml = null; if (filterConfig != null) { // TagSoup it! ByteArrayOutputStream bos = new ByteArrayOutputStream(); InputSource is = new InputSource(r); XHTMLFilter.filterHTML(is, bos, filterConfig); xml = bos.toString(); } else { // Straight through // Read everything into a StringBuffer. StringBuffer chars = new StringBuffer(); char[] buff = new char[512]; int wasRead = 0; do { chars.append(buff, 0, wasRead); // NB: No-op the first time... wasRead = r.read(buff, 0, buff.length); } while (wasRead != -1); // Perform entity replacement. xml = replaceUncleanEntities(chars.toString()); } Document doc = new SAXReader().read(new StringReader(xml)); Iterator it = doc.selectNodes(bodyXpath).iterator(); body.append("<body>"); while (it.hasNext()) { Node n = (Node) it.next(); body.append(n.asXML()); } body.append("</body>"); String name = null; String value = null; it = doc.selectNodes(inputTags).iterator(); while (it.hasNext()) { Element n = (Element) it.next(); name = n.attribute("name").getValue(); value = n.attribute("value").getValue(); attrs.put(name, value); } } catch (Throwable t) { String msg = "Unable to obtain the specified document body: " + path; throw new RuntimeException(msg, t); } return new DocumentData(body.toString(), attrs); } /* * Implementation. */ private Web(String dfltDoc, IResourceFactory fac) { // Assertions. if (dfltDoc == null) { String msg = "Argument 'dfltDoc' cannot be null."; throw new IllegalArgumentException(msg); } if (fac == null) { String msg = "Argument 'fac' cannot be null."; throw new IllegalArgumentException(msg); } // Instance Members. this.dfltDoc = dfltDoc; this.fac = fac; } private static String replaceUncleanEntities(String inpt) { // Assertions. if (inpt == null) { String msg = "Argument 'inpt' cannot be null."; throw new IllegalArgumentException(msg); } String rslt = inpt; for (int i = 0; i < replace.length; i++) { String[] tokens = replace[i]; rslt = rslt.replaceAll(tokens[0], tokens[1]); } return rslt; } }