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.service.diff; import java.util.ArrayList; import java.util.List; import org.apache.commons.lang.StringUtils; import org.apache.ecs.Filter; import org.apache.ecs.filter.CharacterFilter; import org.suigeneris.jrcs.diff.Diff; import org.suigeneris.jrcs.diff.DifferentiationFailedException; import org.suigeneris.jrcs.diff.Revision; import org.suigeneris.jrcs.diff.delta.ChangeDelta; import org.suigeneris.jrcs.diff.delta.Chunk; import org.suigeneris.jrcs.diff.delta.Delta; import org.suigeneris.jrcs.util.ToString; /** * Created by The eXo Platform SAS * Author : viet nguyen * viet.nguyen@exoplatform.com * Jul 30, 2010 */ public class DiffService { /** * Return a list of Delta objects representing line differences in text1 and text2 * @param text1 original content * @param text2 revised content * @return list of Delta objects * @throws DifferentiationFailedException */ public List getDifferencesAsList(String text1, String text2) throws DifferentiationFailedException { if (text1 == null) text1 = ""; if (text2 == null) text2 = ""; return getDeltas(Diff.diff(ToString.stringToArray(text1), ToString.stringToArray(text2))); } /** * Return a list of Delta objects representing word differences in text1 and text2 * @param text1 original content * @param text2 revised content * @return list of Delta objects * @throws DifferentiationFailedException */ public List getWordDifferencesAsList(String text1, String text2) throws DifferentiationFailedException { text1 = text1.replaceAll(" ", "\n"); text2 = text2.replaceAll(" ", "\n"); return getDeltas(Diff.diff(ToString.stringToArray(text1), ToString.stringToArray(text2))); } /** * Return a DiffResult object representing word diffs between text1 and text2 * @param text1 original content * @param text2 revised content * @return list of Delta objects * @throws DifferentiationFailedException */ public DiffResult getWordDifferencesAsHTML(String text1, String text2) throws DifferentiationFailedException { int changes = 0; text1 = "~~PLACEHOLDER~~" + text1 + "~~PLACEHOLDER~~"; text2 = "~~PLACEHOLDER~~" + text2 + "~~PLACEHOLDER~~"; StringBuffer html = new StringBuffer("<div class=\"diffmodifiedline\">"); List list = getWordDifferencesAsList(text1, text2); String[] words = StringUtils.splitPreserveAllTokens(text1, ' '); int cursor = 0; boolean addSpace = false; for (int i = 0; i < list.size(); i++) { if (addSpace) { html.append(" "); addSpace = false; } Delta delta = (Delta) list.get(i); boolean isChangeDelta = (delta instanceof ChangeDelta); int position = delta.getOriginal().anchor(); // First we fill in all text that has not been changed while (cursor < position) { html.append(escape(words[cursor])); html.append(" "); cursor++; } // Then we fill in what has been removed Chunk orig = delta.getOriginal(); if (orig.size() > 0) { html.append("<span class=\"diffremoveword\">"); List chunks = orig.chunk(); for (int j = 0; j < chunks.size(); j++) { if (j > 0) html.append(" "); html.append(escape((String) chunks.get(j))); cursor++; } changes++; html.append("</span>"); addSpace = true; } // Then we fill in what has been added Chunk rev = delta.getRevised(); if (rev.size() > 0) { html.append("<span class=\"diffaddword\">"); List chunks = rev.chunk(); for (int j = 0; j < chunks.size(); j++) { if (j > 0) html.append(" "); html.append(escape((String) chunks.get(j))); } // If is changeDelta, only add change 1 times if (!isChangeDelta) changes++; html.append("</span>"); addSpace = true; } } // First we fill in all text that has not been changed while (cursor < words.length) { if (addSpace) html.append(" "); html.append(escape(words[cursor])); addSpace = true; cursor++; } html.append("</div>"); return new DiffResult(html.toString().replaceAll("~~PLACEHOLDER~~", ""), changes); } /** * Return a DiffResult object representing line diffs between text1 and text2 * @param text1 original content * @param text2 revised content * @param allDoc show all document * @return list of Delta objects * @throws DifferentiationFailedException */ public DiffResult getDifferencesAsHTML(String text1, String text2, boolean allDoc) throws DifferentiationFailedException { StringBuffer html = new StringBuffer("<div class=\"diff\">"); int changes = 0; if (text1 == null) text1 = ""; if (text2 == null) text2 = ""; List list = getDifferencesAsList(text1, text2); String[] lines = ToString.stringToArray(text1); int cursor = 0; boolean addBR = false; for (int i = 0; i < list.size(); i++) { if (addBR) { addBR = false; } Delta delta = (Delta) list.get(i); int position = delta.getOriginal().anchor(); // First we fill in all text that has not been changed while (cursor < position) { if (allDoc) { html.append("<div class=\"diffunmodifiedline\">"); String text = escape(lines[cursor]); if (text.equals("")) text = " "; html.append(text); html.append("</div>"); } cursor++; } // Then we fill in what has been removed Chunk orig = delta.getOriginal(); Chunk rev = delta.getRevised(); if (orig.size() > 0) { List chunks = orig.chunk(); int j2 = 0; for (int j = 0; j < chunks.size(); j++) { String origline = (String) chunks.get(j); // if (j>0) // html.append("<br/>"); List revchunks = rev.chunk(); String revline = ""; while ("".equals(revline)) { revline = (j2 >= revchunks.size()) ? null : (String) revchunks.get(j2); j2++; } if (revline != null) { DiffResult diffLine = getWordDifferencesAsHTML(origline, revline); html.append(diffLine.getDiffHTML()); rev.chunk().remove(revline); changes += diffLine.getChanges(); } else { html.append("<div class=\"diffmodifiedline\">"); if (origline.equals("")) { html.append("<pre class=\"diffremoveword\">"); html.append(" "); html.append("</pre>"); } else { html.append("<span class=\"diffremoveword\">"); html.append(escape(origline)); html.append("</span>"); } html.append("</div>"); changes++; } addBR = true; cursor++; } } // Then we fill in what has been added if (rev.size() > 0) { List chunks = rev.chunk(); for (int j = 0; j < chunks.size(); j++) { String revline = (String) chunks.get(j); html.append("<div class=\"diffmodifiedline\">"); if (revline.equals("")) { html.append("<pre class=\"diffaddword\">"); html.append(" "); html.append("</pre>"); } else { html.append("<span class=\"diffaddword\">"); html.append(escape(revline)); html.append("</span>"); } html.append("</div>"); changes++; } addBR = true; } } // First we fill in all text that has not been changed if (allDoc) { while (cursor < lines.length) { html.append("<div class=\"diffunmodifiedline\">"); String text = escape(lines[cursor]); if (text.equals("")) text = " "; html.append(text); html.append("</div>"); cursor++; } } html.append("</div>"); return new DiffResult(html.toString(), changes); } protected List getDeltas(Revision rev) { ArrayList list = new ArrayList(); for (int i = 0; i < rev.size(); i++) { list.add(rev.getDelta(i)); } return list; } protected String escape(String text) { Filter filter = new CharacterFilter(); String scontent = filter.process(text); return scontent; } }