Java tutorial
/* * This file is part of "SnipSnap Radeox Rendering Engine". * * Copyright (c) 2002 Stephan J. Schmidt, Matthias L. Jugel * All Rights Reserved. * * Please visit http://radeox.org/ for updates and contact. * * --LICENSE NOTICE-- * 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. * --LICENSE NOTICE-- */ package org.radeox.filter; import java.io.IOException; import java.io.Writer; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.radeox.Messages; import org.radeox.api.engine.RenderEngine; import org.radeox.api.engine.WikiRenderEngine; import org.radeox.filter.context.FilterContext; import org.radeox.filter.interwiki.InterWiki; import org.radeox.filter.regex.LocaleRegexTokenFilter; import org.radeox.regex.MatchResult; import org.radeox.util.Encoder; import org.radeox.util.StringBufferWriter; /* * LinkTestFilter finds [text] in its input and transforms this to <a * href="text">...</a> if the wiki page exists. If not it adds a [create text] * to the output. @author stephan @team sonicteam * * @version $Id: LinkTestFilter.java 7707 2006-04-12 17:30:19Z * ian@caret.cam.ac.uk $ */ public class LinkTestFilter extends LocaleRegexTokenFilter { private static Log log = LogFactory.getLog(LinkTestFilter.class); /** * The regular expression for detecting WikiLinks. Overwrite in subclass to * support other link styles like OldAndUglyWikiLinking :-) * /[A-Z][a-z]+([A-Z][a-z]+)+/ wikiPattern = "\\[(.*?)\\]"; */ protected String getLocaleKey() { return "filter.linktest"; //$NON-NLS-1$ } public void handleMatch(StringBuffer buffer, MatchResult result, FilterContext context) { RenderEngine engine = context.getRenderContext().getRenderEngine(); if (engine instanceof WikiRenderEngine) { WikiRenderEngine wikiEngine = (WikiRenderEngine) engine; Writer writer = new StringBufferWriter(buffer); String name = result.group(1); if (name != null) { // User probably wrote [http://radeox.org] instead of // http://radeox.org if (name.indexOf("http://") != -1) //$NON-NLS-1$ { try { writer.write(Messages.getString("LinkTestFilter.2")); //$NON-NLS-1$ } catch (IOException e) { // Do nothing. Give up. } return; } // Is there an alias like [alias|link] ? int pipeIndex = name.indexOf('|'); String alias = ""; //$NON-NLS-1$ if (-1 != pipeIndex) { alias = Encoder.unescape(name.substring(0, pipeIndex).trim()); name = name.substring(pipeIndex + 1).trim(); } Pattern p = Pattern.compile("(.*)(?<!\\&)\\#(.*)"); //$NON-NLS-1$ Matcher m = p.matcher(name); String hash = ""; //$NON-NLS-1$ if (m.matches()) { hash = Encoder.unescape(m.group(2)); char[] hashChars = hash.toCharArray(); int end = 0; for (int i = 0; i < hashChars.length; i++) { if (Character.isLetterOrDigit(hashChars[i])) { hashChars[end++] = hashChars[i]; } } if (end > 0) { hash = new String(hashChars, 0, end); } name = m.group(1); } int colonIndex = name.indexOf(':'); // typed link ? if (-1 != colonIndex) { // for now throw away the type information name = name.substring(colonIndex + 1); } int atIndex = name.lastIndexOf('@'); // InterWiki link ? if (-1 != atIndex) { String extSpace = Encoder.unescape(name.substring(atIndex + 1)); // known external space ? InterWiki interWiki = InterWiki.getInstance(); if (interWiki.contains(extSpace)) { name = Encoder.unescape(name.substring(0, atIndex)); String view; if (-1 != pipeIndex) { view = alias; } else { view = name + "@" + extSpace; //$NON-NLS-1$ } try { if (name.indexOf('@') > -1) { addAtSignError(buffer); } else if (hash.length() > 0) { interWiki.expand(writer, extSpace, name, view, hash); } else { interWiki.expand(writer, extSpace, name, view); } } catch (IOException e) { log.debug("InterWiki " + extSpace + " not found."); //$NON-NLS-1$ //$NON-NLS-2$ } } else { buffer.append("[<span class=\"error\">"); //$NON-NLS-1$ buffer.append(result.group(1)); buffer.append("?</span>]"); //$NON-NLS-1$ } } else { // internal link name = Encoder.unescape(name); if (name.indexOf('@') > -1) { addAtSignError(buffer); } else if (wikiEngine.exists(name) || ("".equals(name) && !("".equals(hash)))) //$NON-NLS-1$ //$NON-NLS-2$ { if ("".equals(name) && !("".equals(hash))) { //$NON-NLS-1$ //$NON-NLS-2$ name = (String) context.getRenderContext() .get("uk.ac.cam.caret.sakai.rwiki.service.api.model.RWikiObject.name"); //$NON-NLS-1$ } String view = getWikiView(name, hash); if (-1 != pipeIndex) { view = alias; } // Do not add hash if an alias was given if (hash.length() > 0) { wikiEngine.appendLink(buffer, name, view, hash); } else { wikiEngine.appendLink(buffer, name, view); } } else if (wikiEngine.showCreate()) { String view = getWikiView(name, ""); //$NON-NLS-1$ if (-1 != pipeIndex) { view = alias; } wikiEngine.appendCreateLink(buffer, name, view); } else { // cannot display/create wiki, so just display the text buffer.append(Encoder.escape(name)); } } } else { buffer.append(Encoder.escape(result.group(0))); } } } private void addAtSignError(StringBuffer buffer) { buffer.append("<span class=\"error\">"); //$NON-NLS-1$ buffer.append(Messages.getString("LinkTestFilter.1")); buffer.append("</span>"); //$NON-NLS-1$ } /** * Returns the view of the wiki name that is shown to the user. Overwrite to * support other views for example transform "WikiLinking" to "Wiki * Linking". Does nothing by default. * * @return view The view of the wiki name */ protected String getWikiView(String name, String hash) { if (!"".equals(hash)) //$NON-NLS-1$ { return name + "#" + hash; //$NON-NLS-1$ } return name; } }