Java tutorial
/* * Copyright (C) 2003-2010 eXo Platform SAS. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Affero General Public License * as published by the Free Software Foundation; either version 3 * 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 program; if not, see<http://www.gnu.org/licenses/>. */ package org.exoplatform.wiki.rendering.render.confluence; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.apache.commons.lang.StringUtils; import org.xwiki.rendering.listener.chaining.BlockStateChainingListener; /** * Created by The eXo Platform SAS * Author : viet nguyen * viet.nguyen@exoplatform.com * Jul 2, 2010 */ /** * Escape characters that would be confused for Confluence wiki syntax if they were not escaped. */ public class ConfluenceSyntaxEscapeHandler { public static final Pattern STARLISTEND_PATTERN = Pattern.compile("(\\**([:;]*|1+\\.)?\\p{Blank})"); private static final Pattern LIST_PATTERN = Pattern .compile("\\p{Blank}*((\\*+[:;]*)|([1*]+\\.[:;]*)|([:;]+))\\p{Blank}+"); private static final Pattern QUOTE_PATTERN = Pattern.compile("(\\>+)"); private static final Pattern HEADER_PATTERN = Pattern.compile("\\p{Blank}*(=+)"); private static final Pattern TABLE_PATTERN = Pattern.compile("\\p{Blank}*(\\||!!)"); private static final Pattern DOUBLE_CHARS_PATTERN = Pattern .compile("\\/\\/|\\*\\*|__|--|\\^\\^|,,|##|\\\\\\\\"); public static final String ESCAPE_CHAR = "~"; private boolean beforeLink = false; private boolean onNewLine = true; public void setOnNewLine(boolean onNewLine) { this.onNewLine = onNewLine; } public boolean isOnNewLine() { return this.onNewLine; } public void escape(StringBuffer accumulatedBuffer, ConfluenceSyntaxListenerChain listenerChain, boolean escapeLastChar, Pattern escapeFirstIfMatching) { BlockStateChainingListener blockStateListener = listenerChain.getBlockStateChainingListener(); // Escape tilde symbol (i.e. the escape character). // Note: This needs to be the first replacement since other replacements below also use the tilde symbol replaceAll(accumulatedBuffer, ESCAPE_CHAR, ESCAPE_CHAR + ESCAPE_CHAR); // When in a paragraph we need to escape symbols that are at beginning of lines and that could be confused // with list items, headers or tables. if (blockStateListener.isInLine() && isOnNewLine()) { // Look for list pattern at beginning of line and escape the first character only (it's enough) escapeFirstMatchedCharacter(LIST_PATTERN, accumulatedBuffer); // Look for header pattern at beginning of line and escape the first character only (it's enough) escapeFirstMatchedCharacter(HEADER_PATTERN, accumulatedBuffer); // Look for table character patterns at beginning of line and escape the first character only (it's enough) escapeFirstMatchedCharacter(TABLE_PATTERN, accumulatedBuffer); // Look for quote pattern at beginning of line and escape the first character only (it's enough) escapeFirstMatchedCharacter(QUOTE_PATTERN, accumulatedBuffer); } // Escape table characters if (blockStateListener.isInTable()) { replaceAll(accumulatedBuffer, "|", ESCAPE_CHAR + "|"); replaceAll(accumulatedBuffer, "||", ESCAPE_CHAR + "|" + ESCAPE_CHAR + "|"); } if (escapeFirstIfMatching != null) { escapeFirstMatchedCharacter(escapeFirstIfMatching, accumulatedBuffer); } // When in a header we need to escape "=" symbols since otherwise they would // be confused for end of section characters. if (blockStateListener.isInHeader()) { replaceAll(accumulatedBuffer, "=", ESCAPE_CHAR + "="); } // Escape verbatim "{{{" replaceAll(accumulatedBuffer, "{{{", ESCAPE_CHAR + "{" + ESCAPE_CHAR + "{" + ESCAPE_CHAR + "{"); // Escape "{{" replaceAll(accumulatedBuffer, "{{", ESCAPE_CHAR + "{" + ESCAPE_CHAR + "{"); // Escape groups replaceAll(accumulatedBuffer, "(((", ESCAPE_CHAR + "(" + ESCAPE_CHAR + "(" + ESCAPE_CHAR + "("); replaceAll(accumulatedBuffer, ")))", ESCAPE_CHAR + ")" + ESCAPE_CHAR + ")" + ESCAPE_CHAR + ")"); // Escape reserved keywords Matcher matcher = DOUBLE_CHARS_PATTERN.matcher(accumulatedBuffer.toString()); for (int i = 0; matcher.find(); i = i + 2) { accumulatedBuffer.replace(matcher.start() + i, matcher.end() + i, ESCAPE_CHAR + matcher.group().charAt(0) + ESCAPE_CHAR + matcher.group().charAt(1)); } // Escape ":" in "image:something", "attach:something" and "mailto:something" // Note: even though there are some restriction in the URI specification as to what character is valid after // the ":" character following the scheme we only check for characters greater than the space symbol for // simplicity. escapeURI(accumulatedBuffer, "image:"); escapeURI(accumulatedBuffer, "attach:"); escapeURI(accumulatedBuffer, "mailto:"); // Escape last character if we're told to do so. This is to handle cases such as: // - onWord("hello:") followed by onFormat(ITALIC) which would lead to "hello://" if the ":" wasn't escaped // - onWord("{") followed by onMacro() which would lead to "{{{" if the "{" wasn't escaped if (escapeLastChar) { accumulatedBuffer.insert(accumulatedBuffer.length() - 1, '~'); } // Escape begin link replaceAll(accumulatedBuffer, "[", ESCAPE_CHAR + "["); // Escape link label int linkLevel = getLinkLevel(listenerChain); if (linkLevel > 0) { // This need to be done after anything else because link label add another level of escaping (escaped as // link label and then escaped as wiki content). String escape = StringUtils.repeat(ESCAPE_CHAR, linkLevel); replaceAll(accumulatedBuffer, ESCAPE_CHAR, escape + ESCAPE_CHAR); replaceAll(accumulatedBuffer, "]", escape + "]"); replaceAll(accumulatedBuffer, "^", escape + "^"); replaceAll(accumulatedBuffer, "|", escape + "|"); } } private int getLinkLevel(ConfluenceSyntaxListenerChain listenerChain) { int linkDepth = listenerChain.getBlockStateChainingListener().getLinkDepth(); if (this.beforeLink) { --linkDepth; } return linkDepth; } public void setBeforeLink(boolean beforeLink) { this.beforeLink = beforeLink; } private void escapeURI(StringBuffer accumulatedBuffer, String match) { int pos = accumulatedBuffer.indexOf(match); if (pos > -1 && accumulatedBuffer.length() > pos + match.length() && accumulatedBuffer.charAt(pos + match.length()) > 32) { // Escape the ":" symbol accumulatedBuffer.replace(pos + match.length() - 1, pos + match.length(), "~:"); } } private void replaceAll(StringBuffer accumulatedBuffer, String match, String replacement) { int pos = -replacement.length(); while ((pos + replacement.length() < accumulatedBuffer.length()) && ((pos = accumulatedBuffer.indexOf(match, pos + replacement.length())) != -1)) { accumulatedBuffer.replace(pos, pos + match.length(), replacement); } } private void escapeFirstMatchedCharacter(Pattern pattern, StringBuffer accumulatedBuffer) { Matcher matcher = pattern.matcher(accumulatedBuffer); if (matcher.lookingAt()) { // Escape the first character accumulatedBuffer.replace(matcher.start(1), matcher.start(1) + 1, ESCAPE_CHAR + matcher.group(1).charAt(0)); } } }