itextpdf.jar is a component in iText 5 Java library to provide core functionalities. iText Java library allows you to generate and manage PDF documents.

The Source Code files are provided at iText GitHub site.

You can compile it to generate your JAR file, using pom.xml as the build configuration file.

The source code of itextpdf-5.5.14.jar is provided below:

⏎ com/itextpdf/text/pdf/PdfPageLabels.java

/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2020 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;

import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.error_messages.MessageLocalization;
import com.itextpdf.text.factories.RomanAlphabetFactory;
import com.itextpdf.text.factories.RomanNumberFactory;

/** Page labels are used to identify each
 * page visually on the screen or in print.
 * @author  Paulo Soares
 */
public class PdfPageLabels {

    /** Logical pages will have the form 1,2,3,...
     */
    public static final int DECIMAL_ARABIC_NUMERALS = 0;
    /** Logical pages will have the form I,II,III,IV,...
     */
    public static final int UPPERCASE_ROMAN_NUMERALS = 1;
    /** Logical pages will have the form i,ii,iii,iv,...
     */
    public static final int LOWERCASE_ROMAN_NUMERALS = 2;
    /** Logical pages will have the form of uppercase letters
     * (A to Z for the first 26 pages, AA to ZZ for the next 26, and so on)
     */
    public static final int UPPERCASE_LETTERS = 3;
    /** Logical pages will have the form of uppercase letters
     * (a to z for the first 26 pages, aa to zz for the next 26, and so on)
     */
    public static final int LOWERCASE_LETTERS = 4;
    /** No logical page numbers are generated but fixed text may
     * still exist
     */
    public static final int EMPTY = 5;
    /** Dictionary values to set the logical page styles
     */
    static PdfName numberingStyle[] = new PdfName[]{PdfName.D, PdfName.R,
                new PdfName("r"), PdfName.A, new PdfName("a")};
    /** The sequence of logical pages. Will contain at least a value for page 1
     */
    private HashMap<Integer, PdfDictionary> map;

    /** Creates a new PdfPageLabel with a default logical page 1
     */
    public PdfPageLabels() {
        map = new HashMap<Integer, PdfDictionary>();
        addPageLabel(1, DECIMAL_ARABIC_NUMERALS, null, 1);
    }

    /** Adds or replaces a page label.
     * @param page the real page to start the numbering. First page is 1
     * @param numberStyle the numbering style such as LOWERCASE_ROMAN_NUMERALS
     * @param text the text to prefix the number. Can be <CODE>null</CODE> or empty
     * @param firstPage the first logical page number
     */
    public void addPageLabel(int page, int numberStyle, String text, int firstPage) {
        if (page < 1 || firstPage < 1)
            throw new IllegalArgumentException(MessageLocalization.getComposedMessage("in.a.page.label.the.page.numbers.must.be.greater.or.equal.to.1"));
        PdfDictionary dic = new PdfDictionary();
        if (numberStyle >= 0 && numberStyle < numberingStyle.length)
            dic.put(PdfName.S, numberingStyle[numberStyle]);
        if (text != null)
            dic.put(PdfName.P, new PdfString(text, PdfObject.TEXT_UNICODE));
        //Not adding the first page by default since 1 is the default value
        if(firstPage !=1)
            dic.put(PdfName.ST, new PdfNumber(firstPage));
        map.put(Integer.valueOf(page - 1), dic);
    }
    
    /** Adds or replaces a page label.
     * @param page the real page to start the numbering. First page is 1
     * @param numberStyle the numbering style such as LOWERCASE_ROMAN_NUMERALS
     * @param text the text to prefix the number. Can be <CODE>null</CODE> or empty
     * @param firstPage the first logical page number
     * @param includeFirstPage If true, the page label will be added to the first page if it is page 1.  
     * 	 If the first page is 1 and this value is false, the value will not be added to the dictionary.  
     */
    public void addPageLabel(int page, int numberStyle, String text, int firstPage, boolean includeFirstPage) {
        if (page < 1 || firstPage < 1)
            throw new IllegalArgumentException(MessageLocalization.getComposedMessage("in.a.page.label.the.page.numbers.must.be.greater.or.equal.to.1"));
        PdfDictionary dic = new PdfDictionary();
        if (numberStyle >= 0 && numberStyle < numberingStyle.length)
            dic.put(PdfName.S, numberingStyle[numberStyle]);
        if (text != null)
            dic.put(PdfName.P, new PdfString(text, PdfObject.TEXT_UNICODE));
        if(firstPage != 1 || includeFirstPage)
            dic.put(PdfName.ST, new PdfNumber(firstPage));
        map.put(Integer.valueOf(page - 1), dic);
    }

    /** Adds or replaces a page label. The first logical page has the default
     * of 1.
     * @param page the real page to start the numbering. First page is 1
     * @param numberStyle the numbering style such as LOWERCASE_ROMAN_NUMERALS
     * @param text the text to prefix the number. Can be <CODE>null</CODE> or empty
     */
    public void addPageLabel(int page, int numberStyle, String text) {
        addPageLabel(page, numberStyle, text, 1);
    }

    /** Adds or replaces a page label. There is no text prefix and the first
     * logical page has the default of 1.
     * @param page the real page to start the numbering. First page is 1
     * @param numberStyle the numbering style such as LOWERCASE_ROMAN_NUMERALS
     */
    public void addPageLabel(int page, int numberStyle) {
        addPageLabel(page, numberStyle, null, 1);
    }

    /** Adds or replaces a page label.
     */
    public void addPageLabel(PdfPageLabelFormat format) {
        addPageLabel(format.physicalPage, format.numberStyle, format.prefix, format.logicalPage);
    }

    /** Removes a page label. The first page label can not be removed, only changed.
     * @param page the real page to remove
     */
    public void removePageLabel(int page) {
        if (page <= 1)
            return;
        map.remove(Integer.valueOf(page - 1));
    }

    /** Gets the page label dictionary to insert into the document.
     * @return the page label dictionary
     */
    public PdfDictionary getDictionary(PdfWriter writer) {
        try {
            return PdfNumberTree.writeTree(map, writer);
        }
        catch (IOException e) {
            throw new ExceptionConverter(e);
        }
    }

    /**
     * Retrieves the page labels from a PDF as an array of String objects.
     * @param reader a PdfReader object that has the page labels you want to retrieve
     * @return a String array or <code>null</code> if no page labels are present
     */
    public static String[] getPageLabels(PdfReader reader) {
        int n = reader.getNumberOfPages();

        PdfDictionary dict = reader.getCatalog();
        PdfDictionary labels = (PdfDictionary)PdfReader.getPdfObjectRelease(dict.get(PdfName.PAGELABELS));

        if (labels == null)
            return null;

        String[] labelstrings = new String[n];

        HashMap<Integer, PdfObject> numberTree = PdfNumberTree.readTree(labels);

        int pagecount = 1;
        Integer current;
        String prefix = "";
        char type = 'D';
        for (int i = 0; i < n; i++) {
            current = Integer.valueOf(i);
            if (numberTree.containsKey(current)) {
                PdfDictionary d = (PdfDictionary)PdfReader.getPdfObjectRelease(numberTree.get(current));
                if (d.contains(PdfName.ST)) {
                    pagecount = ((PdfNumber)d.get(PdfName.ST)).intValue();
                }
                else {
                    pagecount = 1;
                }
                if (d.contains(PdfName.P)) {
                    prefix = ((PdfString)d.get(PdfName.P)).toUnicodeString();
                }
                else {
                    prefix = "";
                }
                if (d.contains(PdfName.S)) {
                    type = ((PdfName)d.get(PdfName.S)).toString().charAt(1);
                }
                else {
                    type = 'e';
                }
            }
            switch(type) {
                default:
                    labelstrings[i] = prefix + pagecount;
                    break;
                case 'R':
                    labelstrings[i] = prefix + RomanNumberFactory.getUpperCaseString(pagecount);
                    break;
                case 'r':
                    labelstrings[i] = prefix + RomanNumberFactory.getLowerCaseString(pagecount);
                    break;
                case 'A':
                    labelstrings[i] = prefix + RomanAlphabetFactory.getUpperCaseString(pagecount);
                    break;
                case 'a':
                    labelstrings[i] = prefix + RomanAlphabetFactory.getLowerCaseString(pagecount);
                    break;
                case 'e':
                    labelstrings[i] = prefix;
                    break;
            }
            pagecount++;
        }
        return labelstrings;
    }

    /**
     * Retrieves the page labels from a PDF as an array of {@link PdfPageLabelFormat} objects.
     * @param reader a PdfReader object that has the page labels you want to retrieve
     * @return	a PdfPageLabelEntry array, containing an entry for each format change
     * or <code>null</code> if no page labels are present
     */
    public static PdfPageLabelFormat[] getPageLabelFormats(PdfReader reader) {
        PdfDictionary dict = reader.getCatalog();
        PdfDictionary labels = (PdfDictionary)PdfReader.getPdfObjectRelease(dict.get(PdfName.PAGELABELS));
        if (labels == null)
            return null;
        HashMap<Integer, PdfObject> numberTree = PdfNumberTree.readTree(labels);
        Integer numbers[] = new Integer[numberTree.size()];
        numbers = numberTree.keySet().toArray(numbers);
        Arrays.sort(numbers);
        PdfPageLabelFormat[] formats = new PdfPageLabelFormat[numberTree.size()];
        String prefix;
        int numberStyle;
        int pagecount;
        for (int k = 0; k < numbers.length; ++k) {
            Integer key = numbers[k];
            PdfDictionary d = (PdfDictionary)PdfReader.getPdfObjectRelease(numberTree.get(key));
            if (d.contains(PdfName.ST)) {
                pagecount = ((PdfNumber)d.get(PdfName.ST)).intValue();
            } else {
                pagecount = 1;
            }
            if (d.contains(PdfName.P)) {
                prefix = ((PdfString)d.get(PdfName.P)).toUnicodeString();
            } else {
                prefix = "";
            }
            if (d.contains(PdfName.S)) {
                char type = ((PdfName)d.get(PdfName.S)).toString().charAt(1);
                switch(type) {
                    case 'R': numberStyle = UPPERCASE_ROMAN_NUMERALS; break;
                    case 'r': numberStyle = LOWERCASE_ROMAN_NUMERALS; break;
                    case 'A': numberStyle = UPPERCASE_LETTERS; break;
                    case 'a': numberStyle = LOWERCASE_LETTERS; break;
                    default: numberStyle = DECIMAL_ARABIC_NUMERALS; break;
                }
            } else {
                numberStyle = EMPTY;
            }
            formats[k] = new PdfPageLabelFormat(key.intValue()+1, numberStyle, prefix, pagecount);
        }
        return formats;
    }

    public static class PdfPageLabelFormat {

        public int physicalPage;
        public int numberStyle;
        public String prefix;
        public int logicalPage;

        /** Creates a page label format.
         * @param physicalPage the real page to start the numbering. First page is 1
         * @param numberStyle the numbering style such as LOWERCASE_ROMAN_NUMERALS
         * @param prefix the text to prefix the number. Can be <CODE>null</CODE> or empty
         * @param logicalPage the first logical page number
         */
        public PdfPageLabelFormat(int physicalPage, int numberStyle, String prefix, int logicalPage) {
            this.physicalPage = physicalPage;
            this.numberStyle = numberStyle;
            this.prefix = prefix;
            this.logicalPage = logicalPage;
        }
        
        @Override
        public String toString() {
            return String.format("Physical page %s: style: %s; prefix '%s'; logical page: %s", physicalPage, numberStyle, prefix, logicalPage);
        }
    }
}

⏎ com/itextpdf/text/pdf/PdfPageLabels.java

Or download all of them as a single archive file:

File name: itextpdf-5.5.14-fyi.zip
File size: 2163839 bytes
Release date: 2009-10-09
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