Java tutorial
/* * * This file is part of the iText (R) project. Copyright (c) 1998-2019 iText Group NV * Authors: Bruno Lowagie, Paulo Soares, et al. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License version 3 * as published by the Free Software Foundation with the addition of the * following permission added to Section 15 as permitted in Section 7(a): * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT * OF THIRD PARTY RIGHTS * * 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 Affero General Public License for more details. * You should have received a copy of the GNU Affero General Public License * along with this program; if not, see http://www.gnu.org/licenses or write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA, 02110-1301 USA, or download the license from the following URL: * http://itextpdf.com/terms-of-use/ * * The interactive user interfaces in modified source and object code versions * of this program must display Appropriate Legal Notices, as required under * Section 5 of the GNU Affero General Public License. * * In accordance with Section 7(b) of the GNU Affero General Public License, * a covered work must retain the producer line in every PDF that is created * or manipulated using iText. * * You can be released from the requirements of the license by purchasing * a commercial license. Buying such a license is mandatory as soon as you * develop commercial activities involving the iText software without * disclosing the source code of your own applications. * These activities include: offering paid services to customers as an ASP, * serving PDFs on the fly in a web application, shipping iText with a closed * source product. * * For more information, please contact iText Software Corp. at this * address: sales@itextpdf.com */ package com.itextpdf.text.pdf; import java.io.IOException; import java.util.Arrays; import java.util.HashMap; /** * Creates a name tree. * @author Paulo Soares */ public class PdfNameTree { private static final int leafSize = 64; /** * Writes a name tree to a PdfWriter. * @param items the item of the name tree. The key is a <CODE>String</CODE> * and the value is a <CODE>PdfObject</CODE>. Note that although the * keys are strings only the lower byte is used and no check is made for chars * with the same lower byte and different upper byte. This will generate a wrong * tree name. * @param writer the writer * @throws IOException on error * @return the dictionary with the name tree. This dictionary is the one * generally pointed to by the key /Dests, for example */ public static PdfDictionary writeTree(HashMap<String, ? extends PdfObject> items, PdfWriter writer) throws IOException { if (items.isEmpty()) return null; String names[] = new String[items.size()]; names = items.keySet().toArray(names); Arrays.sort(names); if (names.length <= leafSize) { PdfDictionary dic = new PdfDictionary(); PdfArray ar = new PdfArray(); for (int k = 0; k < names.length; ++k) { ar.add(new PdfString(names[k], null)); ar.add(items.get(names[k])); } dic.put(PdfName.NAMES, ar); return dic; } int skip = leafSize; PdfIndirectReference kids[] = new PdfIndirectReference[(names.length + leafSize - 1) / leafSize]; for (int k = 0; k < kids.length; ++k) { int offset = k * leafSize; int end = Math.min(offset + leafSize, names.length); PdfDictionary dic = new PdfDictionary(); PdfArray arr = new PdfArray(); arr.add(new PdfString(names[offset], null)); arr.add(new PdfString(names[end - 1], null)); dic.put(PdfName.LIMITS, arr); arr = new PdfArray(); for (; offset < end; ++offset) { arr.add(new PdfString(names[offset], null)); arr.add(items.get(names[offset])); } dic.put(PdfName.NAMES, arr); kids[k] = writer.addToBody(dic).getIndirectReference(); } int top = kids.length; while (true) { if (top <= leafSize) { PdfArray arr = new PdfArray(); for (int k = 0; k < top; ++k) arr.add(kids[k]); PdfDictionary dic = new PdfDictionary(); dic.put(PdfName.KIDS, arr); return dic; } skip *= leafSize; int tt = (names.length + skip - 1) / skip; for (int k = 0; k < tt; ++k) { int offset = k * leafSize; int end = Math.min(offset + leafSize, top); PdfDictionary dic = new PdfDictionary(); PdfArray arr = new PdfArray(); arr.add(new PdfString(names[k * skip], null)); arr.add(new PdfString(names[Math.min((k + 1) * skip, names.length) - 1], null)); dic.put(PdfName.LIMITS, arr); arr = new PdfArray(); for (; offset < end; ++offset) { arr.add(kids[offset]); } dic.put(PdfName.KIDS, arr); kids[k] = writer.addToBody(dic).getIndirectReference(); } top = tt; } } private static PdfString iterateItems(PdfDictionary dic, HashMap<String, PdfObject> items, PdfString leftOverString) { PdfArray nn = (PdfArray) PdfReader.getPdfObjectRelease(dic.get(PdfName.NAMES)); if (nn != null) { for (int k = 0; k < nn.size(); ++k) { PdfString s; if (leftOverString == null) s = (PdfString) PdfReader.getPdfObjectRelease(nn.getPdfObject(k++)); else { // this is the leftover string from the previous loop s = leftOverString; leftOverString = null; } if (k < nn.size()) // could have a mistake int the pdf file items.put(PdfEncodings.convertToString(s.getBytes(), null), nn.getPdfObject(k)); else return s; } } else if ((nn = (PdfArray) PdfReader.getPdfObjectRelease(dic.get(PdfName.KIDS))) != null) { for (int k = 0; k < nn.size(); ++k) { PdfDictionary kid = (PdfDictionary) PdfReader.getPdfObjectRelease(nn.getPdfObject(k)); leftOverString = iterateItems(kid, items, leftOverString); } } return null; } public static HashMap<String, PdfObject> readTree(PdfDictionary dic) { HashMap<String, PdfObject> items = new HashMap<String, PdfObject>(); if (dic != null) iterateItems(dic, items, null); return items; } }