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/TaggedPdfReaderTool.java

/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2020 iText Group NV
 * Authors: Bruno Lowagie, 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 com.itextpdf.text.error_messages.MessageLocalization;
import com.itextpdf.text.pdf.*;
import com.itextpdf.text.xml.XMLUtil;

import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Set;

/**
 * Converts a tagged PDF document into an XML file.
 * 
 * @since 5.0.2
 */
public class TaggedPdfReaderTool {

	/** The reader object from which the content streams are read. */
	protected PdfReader reader;
	/** The writer object to which the XML will be written */
	protected PrintWriter out;

	/**
	 * Parses a string with structured content.
	 * 
	 * @param reader
	 *            the PdfReader that has access to the PDF file
	 * @param os
	 *            the OutputStream to which the resulting xml will be written
	 * @param charset
	 *            the charset to encode the data
     * @since 5.0.5
	 */
	public void convertToXml(PdfReader reader, OutputStream os, String charset)
			throws IOException {
		this.reader = reader;
        OutputStreamWriter outs = new OutputStreamWriter(os, charset);
		out = new PrintWriter(outs);
		// get the StructTreeRoot from the root object
		PdfDictionary catalog = reader.getCatalog();
		PdfDictionary struct = catalog.getAsDict(PdfName.STRUCTTREEROOT);
		if (struct == null)
			throw new IOException(MessageLocalization.getComposedMessage("no.structtreeroot.found"));
		// Inspect the child or children of the StructTreeRoot
		inspectChild(struct.getDirectObject(PdfName.K));
		out.flush();
		out.close();
	}

	/**
	 * Parses a string with structured content. The output is done using the
     * current charset.
	 *
	 * @param reader
	 *            the PdfReader that has access to the PDF file
	 * @param os
	 *            the OutputStream to which the resulting xml will be written
	 */
	public void convertToXml(PdfReader reader, OutputStream os)
			throws IOException {
        convertToXml(reader, os, "UTF-8");
    }

    /**
	 * Inspects a child of a structured element. This can be an array or a
	 * dictionary.
	 * 
	 * @param k
	 *            the child to inspect
	 * @throws IOException
	 */
	public void inspectChild(PdfObject k) throws IOException {
		if (k == null)
			return;
		if (k instanceof PdfArray)
			inspectChildArray((PdfArray) k);
		else if (k instanceof PdfDictionary)
			inspectChildDictionary((PdfDictionary) k);
	}

	/**
	 * If the child of a structured element is an array, we need to loop over
	 * the elements.
	 * 
	 * @param k
	 *            the child array to inspect
	 */
	public void inspectChildArray(PdfArray k) throws IOException {
		if (k == null)
			return;
		for (int i = 0; i < k.size(); i++) {
			inspectChild(k.getDirectObject(i));
		}
	}

    /**
     * If the child of a structured element is a dictionary, we inspect the
     * child; we may also draw a tag.
     *
     * @param k
     *            the child dictionary to inspect
     */
    public void inspectChildDictionary(PdfDictionary k) throws IOException {
        inspectChildDictionary(k, false);
    }


	/**
	 * If the child of a structured element is a dictionary, we inspect the
	 * child; we may also draw a tag.
	 * 
	 * @param k
	 *            the child dictionary to inspect
	 */
    public void inspectChildDictionary(PdfDictionary k, boolean inspectAttributes) throws IOException {
        if (k == null)
            return;
        PdfName s = k.getAsName(PdfName.S);
        if (s != null) {
            String tagN = PdfName.decodeName(s.toString());
            String tag = fixTagName(tagN);
            out.print("<");
            out.print(tag);
            if (inspectAttributes) {
                PdfDictionary a = k.getAsDict(PdfName.A);
                if (a != null) {
                    Set<PdfName> keys =  a.getKeys();
                    for (PdfName key : keys) {
                        out.print(' ');
                        PdfObject value = a.get(key);
                        value = PdfReader.getPdfObject(value);
                        out.print(xmlName(key));
                        out.print("=\"");
                        out.print(value.toString());
                        out.print("\"");
                    }
                }
            }
            out.print(">");
            PdfObject alt = k.get(PdfName.ALT);
            if (alt != null && alt.toString() != null) {
                out.print("<alt><![CDATA[");
                out.print(alt.toString().replaceAll("[\\000]*", ""));
                out.print("]]></alt>");
            }
            PdfDictionary dict = k.getAsDict(PdfName.PG);
            if (dict != null)
                parseTag(tagN, k.getDirectObject(PdfName.K), dict);
            inspectChild(k.getDirectObject(PdfName.K));
            out.print("</");
            out.print(tag);
            out.println(">");
        } else
            inspectChild(k.getDirectObject(PdfName.K));
    }

    protected String xmlName(PdfName name) {
        String xmlName = name.toString().replaceFirst("/", "");
        xmlName = Character.toLowerCase(xmlName.charAt(0))
                   + xmlName.substring(1);
        return xmlName;
    }

    private static String fixTagName(String tag) {
        StringBuilder sb = new StringBuilder();
        for (int k = 0; k < tag.length(); ++k) {
            char c = tag.charAt(k);
            boolean nameStart =
                c == ':'
                || (c >= 'A' && c <= 'Z')
                || c == '_'
                || (c >= 'a' && c <= 'z')
                || (c >= '\u00c0' && c <= '\u00d6')
                || (c >= '\u00d8' && c <= '\u00f6')
                || (c >= '\u00f8' && c <= '\u02ff')
                || (c >= '\u0370' && c <= '\u037d')
                || (c >= '\u037f' && c <= '\u1fff')
                || (c >= '\u200c' && c <= '\u200d')
                || (c >= '\u2070' && c <= '\u218f')
                || (c >= '\u2c00' && c <= '\u2fef')
                || (c >= '\u3001' && c <= '\ud7ff')
                || (c >= '\uf900' && c <= '\ufdcf')
                || (c >= '\ufdf0' && c <= '\ufffd');
            boolean nameMiddle =
                c == '-'
                || c == '.'
                || (c >= '0' && c <= '9')
                || c == '\u00b7'
                || (c >= '\u0300' && c <= '\u036f')
                || (c >= '\u203f' && c <= '\u2040')
                || nameStart;
            if (k == 0) {
                if (!nameStart)
                    c = '_';
            }
            else {
                if (!nameMiddle)
                    c = '-';
            }
            sb.append(c);
        }
        return sb.toString();
    }

	/**
	 * Searches for a tag in a page.
	 * 
	 * @param tag
	 *            the name of the tag
	 * @param object
	 *            an identifier to find the marked content
	 * @param page
	 *            a page dictionary
	 * @throws IOException
	 */
	public void parseTag(String tag, PdfObject object, PdfDictionary page)
			throws IOException {
		// if the identifier is a number, we can extract the content right away
		if (object instanceof PdfNumber) {
			PdfNumber mcid = (PdfNumber) object;
			RenderFilter filter = new MarkedContentRenderFilter(mcid.intValue());
			TextExtractionStrategy strategy = new SimpleTextExtractionStrategy();
			FilteredTextRenderListener listener = new FilteredTextRenderListener(
					strategy, filter);
			PdfContentStreamProcessor processor = new PdfContentStreamProcessor(
					listener);
			processor.processContent(PdfReader.getPageContent(page), page
					.getAsDict(PdfName.RESOURCES));
			out.print(XMLUtil.escapeXML(listener.getResultantText(), true));
		}
		// if the identifier is an array, we call the parseTag method
		// recursively
		else if (object instanceof PdfArray) {
			PdfArray arr = (PdfArray) object;
			int n = arr.size();
			for (int i = 0; i < n; i++) {
				parseTag(tag, arr.getPdfObject(i), page);
				if (i < n - 1)
					out.println();
			}
		}
		// if the identifier is a dictionary, we get the resources from the
		// dictionary
		else if (object instanceof PdfDictionary) {
			PdfDictionary mcr = (PdfDictionary) object;
			parseTag(tag, mcr.getDirectObject(PdfName.MCID), mcr
					.getAsDict(PdfName.PG));
		}
	}

}

⏎ com/itextpdf/text/pdf/parser/TaggedPdfReaderTool.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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