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/parser/PdfContentReaderTool.java

/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2020 iText Group NV
 * Authors: Kevin Day, 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.parser;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

import com.itextpdf.text.pdf.PdfDictionary;
import com.itextpdf.text.pdf.PdfName;
import com.itextpdf.text.pdf.PdfObject;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStream;
import com.itextpdf.text.pdf.RandomAccessFileOrArray;

/**
 * Tool that parses the content of a PDF document.
 * @since	2.1.4
 */
public class PdfContentReaderTool {

	/**
	 * Shows the detail of a dictionary.
	 * This is similar to the PdfLister functionality.
	 * @param dic	the dictionary of which you want the detail
	 * @return	a String representation of the dictionary
	 */
    static public String getDictionaryDetail(PdfDictionary dic){
        return getDictionaryDetail(dic, 0);
    }

    /**
     * Shows the detail of a dictionary.
     * @param dic	the dictionary of which you want the detail
     * @param depth	the depth of the current dictionary (for nested dictionaries)
     * @return	a String representation of the dictionary
     */
    static public String getDictionaryDetail(PdfDictionary dic, int depth){
        StringBuffer builder = new StringBuffer();
        builder.append('(');
        List<PdfName> subDictionaries = new ArrayList<PdfName>();
        for (PdfName key: dic.getKeys()) {
            PdfObject val = dic.getDirectObject(key);
            if (val.isDictionary())
                subDictionaries.add(key);
            builder.append(key);
            builder.append('=');
            builder.append(val);
            builder.append(", ");
        }
        if (builder.length() >= 2)
        	builder.setLength(builder.length()-2);
        builder.append(')');
        for (PdfName pdfSubDictionaryName: subDictionaries) {
            builder.append('\n');
            for(int i = 0; i < depth+1; i++){
                builder.append('\t');
            }
            builder.append("Subdictionary ");
            builder.append(pdfSubDictionaryName);
            builder.append(" = ");
            builder.append(getDictionaryDetail(dic.getAsDict(pdfSubDictionaryName), depth+1));
        }
        return builder.toString();
    }

    /**
     * Displays a summary of the entries in the XObject dictionary for the stream
     * @param resourceDic the resource dictionary for the stream
     * @return a string with the summary of the entries
     * @throws IOException
     * @since 5.0.2
     */
    static public String getXObjectDetail(PdfDictionary resourceDic) throws IOException {
        StringBuilder sb = new StringBuilder();
        
        PdfDictionary xobjects = resourceDic.getAsDict(PdfName.XOBJECT);
        if (xobjects == null)
        	return "No XObjects";
        for (PdfName entryName : xobjects.getKeys()) {
            PdfStream xobjectStream = xobjects.getAsStream(entryName);
            
            sb.append("------ " + entryName + " - subtype = " + xobjectStream.get(PdfName.SUBTYPE) + " = " + xobjectStream.getAsNumber(PdfName.LENGTH) + " bytes ------\n");
            
            if (!xobjectStream.get(PdfName.SUBTYPE).equals(PdfName.IMAGE)){
            
                byte[] contentBytes = ContentByteUtils.getContentBytesFromContentObject(xobjectStream);
                
                InputStream is = new ByteArrayInputStream(contentBytes);
                int ch;
                while ((ch = is.read()) != -1){
                    sb.append((char)ch);
                }
    
                sb.append("------ " + entryName + " - subtype = " + xobjectStream.get(PdfName.SUBTYPE) + "End of Content" + "------\n");
            }
        }
       
        return sb.toString();
    }
    
    /**
     * Writes information about a specific page from PdfReader to the specified output stream.
     * @since 2.1.5
     * @param reader    the PdfReader to read the page content from
     * @param pageNum   the page number to read
     * @param out       the output stream to send the content to
     * @throws IOException
     */
    static public void listContentStreamForPage(PdfReader reader, int pageNum, PrintWriter out) throws IOException {
        out.println("==============Page " + pageNum + "====================");
        out.println("- - - - - Dictionary - - - - - -");
        PdfDictionary pageDictionary = reader.getPageN(pageNum);
        out.println(getDictionaryDetail(pageDictionary));

        out.println("- - - - - XObject Summary - - - - - -");
        out.println(getXObjectDetail(pageDictionary.getAsDict(PdfName.RESOURCES)));
        
        out.println("- - - - - Content Stream - - - - - -");
        RandomAccessFileOrArray f = reader.getSafeFile();

        byte[] contentBytes = reader.getPageContent(pageNum, f);
        f.close();

        out.flush();

        InputStream is = new ByteArrayInputStream(contentBytes);
        int ch;
        while ((ch = is.read()) != -1){
            out.print((char)ch);
        }

        out.flush();
        
        out.println("- - - - - Text Extraction - - - - - -");
        String extractedText = PdfTextExtractor.getTextFromPage(reader, pageNum, new LocationTextExtractionStrategy());
        if (extractedText.length() != 0)
            out.println(extractedText);
        else
            out.println("No text found on page " + pageNum);

        out.println();

    }

    /**
     * Writes information about each page in a PDF file to the specified output stream.
     * @since 2.1.5
     * @param pdfFile	a File instance referring to a PDF file
     * @param out       the output stream to send the content to
     * @throws IOException
     */
    static public void listContentStream(File pdfFile, PrintWriter out) throws IOException {
        PdfReader reader = new PdfReader(pdfFile.getCanonicalPath());

        int maxPageNum = reader.getNumberOfPages();

        for (int pageNum = 1; pageNum <= maxPageNum; pageNum++){
            listContentStreamForPage(reader, pageNum, out);
        }

    }

    /**
     * Writes information about the specified page in a PDF file to the specified output stream.
     * @since 2.1.5
     * @param pdfFile   a File instance referring to a PDF file
     * @param pageNum   the page number to read
     * @param out       the output stream to send the content to
     * @throws IOException
     */
    static public void listContentStream(File pdfFile, int pageNum, PrintWriter out) throws IOException {
        PdfReader reader = new PdfReader(pdfFile.getCanonicalPath());

        listContentStreamForPage(reader, pageNum, out);
    }

    /**
     * Writes information about each page in a PDF file to the specified file, or System.out.
     * @param args
     */
    public static void main(String[] args) {
        try{
            if (args.length < 1 || args.length > 3){
                System.out.println("Usage:  PdfContentReaderTool <pdf file> [<output file>|stdout] [<page num>]");
                return;
            }

            PrintWriter writer = new PrintWriter(System.out);
            if (args.length >= 2){
                if (args[1].compareToIgnoreCase("stdout") != 0){
                    System.out.println("Writing PDF content to " + args[1]);
                    writer = new PrintWriter(new FileOutputStream(new File(args[1])));
                }
            }

            int pageNum = -1;
            if (args.length >= 3){
                pageNum = Integer.parseInt(args[2]);
            }

            if (pageNum == -1){
                listContentStream(new File(args[0]), writer);
            } else {
                listContentStream(new File(args[0]), pageNum, writer);
            }
            writer.flush();

            if (args.length >= 2){
                writer.close();
                System.out.println("Finished writing content to " + args[1]);
            }
        } catch (Exception e){
            e.printStackTrace(System.err);
        }
    }

}

⏎ com/itextpdf/text/pdf/parser/PdfContentReaderTool.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
Download 

⇒ iText-2.1.6.jar - iText, a JAVA-PDF library

⇐ iText layout.jar Source Code

⇑ Download and Install iText Java Library

⇑⇑ iText for PDF Generation