Java tutorial
/* * See the NOTICE file distributed with this work for additional * information regarding copyright ownership. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This software 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ package com.xpn.xwiki.plugin.diff; import java.util.ArrayList; import java.util.List; import org.apache.commons.lang3.StringUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.suigeneris.jrcs.diff.Diff; import org.suigeneris.jrcs.diff.Revision; import org.suigeneris.jrcs.diff.delta.Chunk; import org.suigeneris.jrcs.diff.delta.Delta; import org.suigeneris.jrcs.util.ToString; import org.xwiki.xml.XMLUtils; import com.xpn.xwiki.XWikiContext; import com.xpn.xwiki.XWikiException; import com.xpn.xwiki.api.Api; import com.xpn.xwiki.plugin.XWikiDefaultPlugin; import com.xpn.xwiki.plugin.XWikiPluginInterface; /** * @version $Id: 3f980c01abedcd429cf163efa65a93c090dff98b $ */ public class DiffPlugin extends XWikiDefaultPlugin { /** * Log4J logger object to log messages in this class. */ private static final Logger LOGGER = LoggerFactory.getLogger(DiffPlugin.class); /** * {@inheritDoc} * * @see com.xpn.xwiki.plugin.XWikiDefaultPlugin#XWikiDefaultPlugin(String,String,com.xpn.xwiki.XWikiContext) */ public DiffPlugin(String name, String className, XWikiContext context) { super(name, className, context); } /** * {@inheritDoc} * * @see com.xpn.xwiki.plugin.XWikiDefaultPlugin#getName() */ @Override public String getName() { return "diff"; } /** * {@inheritDoc} * * @see com.xpn.xwiki.plugin.XWikiDefaultPlugin#getPluginApi */ @Override public Api getPluginApi(XWikiPluginInterface plugin, XWikiContext context) { return new DiffPluginApi((DiffPlugin) plugin, context); } /** * 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 */ public List getDifferencesAsList(String text1, String text2) throws XWikiException { try { if (text1 == null) { text1 = ""; } if (text2 == null) { text2 = ""; } return getDeltas(Diff.diff(ToString.stringToArray(text1), ToString.stringToArray(text2))); } catch (Exception e) { throw new XWikiException(XWikiException.MODULE_XWIKI_DIFF, XWikiException.ERROR_XWIKI_DIFF_CONTENT_ERROR, "Diff of content generated an exception", e); } } 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) { return XMLUtils.escape(text); } /** * 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 */ public List getWordDifferencesAsList(String text1, String text2) throws XWikiException { try { text1 = text1.replaceAll(" ", "\n"); text2 = text2.replaceAll(" ", "\n"); return getDeltas(Diff.diff(ToString.stringToArray(text1), ToString.stringToArray(text2))); } catch (Exception e) { throw new XWikiException(XWikiException.MODULE_XWIKI_DIFF, XWikiException.ERROR_XWIKI_DIFF_CONTENT_ERROR, "Diff of content generated an exception", e); } } /** * Return an html blocks representing word diffs between text1 and text2 * * @param text1 original content * @param text2 revised content * @return list of Delta objects */ public String getWordDifferencesAsHTML(String text1, String text2) throws XWikiException { 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); 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++; } 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))); } 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 html.toString().replaceAll("~~PLACEHOLDER~~", ""); } /** * Return an html blocks representing line diffs between text1 and text2 * * @param text1 original content * @param text2 revised content * @return list of Delta objects */ public String getDifferencesAsHTML(String text1, String text2) throws XWikiException { return getDifferencesAsHTML(text1, text2, true); } /** * Return an html blocks 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 */ public String getDifferencesAsHTML(String text1, String text2, boolean allDoc) throws XWikiException { StringBuffer html = new StringBuffer("<div class=\"diff\">"); 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(); int j1 = 0; 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 (origline.equals("")) { cursor++; continue; } // 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++; j1++; } if (revline != null) { html.append(getWordDifferencesAsHTML(origline, revline)); } else { html.append("<div class=\"diffmodifiedline\">"); html.append("<span class=\"diffremoveword\">"); html.append(escape(origline)); html.append("</span></div>"); } addBR = true; cursor++; } } // Then we fill in what has been added if (rev.size() > 0) { List chunks = rev.chunk(); for (int j = j1; j < chunks.size(); j++) { // if (j>0) // html.append("<br/>"); html.append("<div class=\"diffmodifiedline\">"); html.append("<span class=\"diffaddword\">"); html.append(escape((String) chunks.get(j))); html.append("</span></div>"); } 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 html.toString(); } }