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/FilterHandlers.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;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import com.itextpdf.text.error_messages.MessageLocalization;
import com.itextpdf.text.exceptions.UnsupportedPdfException;
import com.itextpdf.text.pdf.codec.TIFFConstants;
import com.itextpdf.text.pdf.codec.TIFFFaxDecoder;
import com.itextpdf.text.pdf.codec.TIFFFaxDecompressor;

/**
 * Encapsulates filter behavior for PDF streams.  Classes generally interace with this
 * using the static getDefaultFilterHandlers() method, then obtain the desired {@link FilterHandler}
 * via a lookup.
 * @since 5.0.4
 */
// Dev note:  we eventually want to refactor PdfReader so all of the existing filter functionality is moved into this class
// it may also be better to split the sub-classes out into a separate package 
public final class FilterHandlers {
    
    /**
     * The main interface for creating a new {@link FilterHandler}
     */
    public static interface FilterHandler{
        public byte[] decode(byte[] b, PdfName filterName, PdfObject decodeParams, final PdfDictionary streamDictionary) throws IOException;
    }
    
    /** The default {@link FilterHandler}s used by iText */
    private static final Map<PdfName, FilterHandler> defaults;
    static {
        HashMap<PdfName, FilterHandler> map = new HashMap<PdfName, FilterHandler>();
        
        map.put(PdfName.FLATEDECODE, new Filter_FLATEDECODE());
        map.put(PdfName.FL, new Filter_FLATEDECODE());
        map.put(PdfName.ASCIIHEXDECODE, new Filter_ASCIIHEXDECODE());
        map.put(PdfName.AHX, new Filter_ASCIIHEXDECODE());
        map.put(PdfName.ASCII85DECODE, new Filter_ASCII85DECODE());
        map.put(PdfName.A85, new Filter_ASCII85DECODE());
        map.put(PdfName.LZWDECODE, new Filter_LZWDECODE());
        map.put(PdfName.CCITTFAXDECODE, new Filter_CCITTFAXDECODE());
        map.put(PdfName.CRYPT, new Filter_DoNothing());
        map.put(PdfName.RUNLENGTHDECODE, new Filter_RUNLENGTHDECODE());
        
        defaults = Collections.unmodifiableMap(map);
    }
    
    /**
     * @return the default {@link FilterHandler}s used by iText
     */
    public static Map<PdfName, FilterHandler> getDefaultFilterHandlers(){
        return defaults;
    }

    /**
     * Creates a {@link MemoryLimitsAwareOutputStream} which will be used for decompression of the passed pdf stream.
     *
     * @param streamDictionary the pdf stream which is going to be decompressed.
     * @return the {@link ByteArrayOutputStream} which will be used for decompression of the passed pdf stream
     */
    public static ByteArrayOutputStream enableMemoryLimitsAwareHandler(PdfDictionary streamDictionary) {
        MemoryLimitsAwareOutputStream outputStream = new MemoryLimitsAwareOutputStream();
        MemoryLimitsAwareHandler memoryLimitsAwareHandler = null;
        if (streamDictionary instanceof PRStream && null != ((PRStream) streamDictionary).getReader()) {
            memoryLimitsAwareHandler = ((PRStream) streamDictionary).getReader().getMemoryLimitsAwareHandler();
        } else {
            // We do not reuse some static instance because one can process pdfs in different threads.
            memoryLimitsAwareHandler = new MemoryLimitsAwareHandler();
        }
        if (null != memoryLimitsAwareHandler && memoryLimitsAwareHandler.considerCurrentPdfStream) {
            outputStream.setMaxStreamSize(memoryLimitsAwareHandler.getMaxSizeOfSingleDecompressedPdfStream());
        }
        return outputStream;
    }

    /**
     * Handles FLATEDECODE filter
     */
    private static class Filter_FLATEDECODE implements FilterHandler{
        public byte[] decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary) throws IOException {
            ByteArrayOutputStream out = enableMemoryLimitsAwareHandler(streamDictionary);
            b = PdfReader.FlateDecode(b, out);
            b = PdfReader.decodePredictor(b, decodeParams);
            return b;
        }
    }
    
    /**
     * Handles ASCIIHEXDECODE filter
     */
    private static class Filter_ASCIIHEXDECODE implements FilterHandler{
        public byte[] decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary) throws IOException {
            ByteArrayOutputStream out = enableMemoryLimitsAwareHandler(streamDictionary);
            b = PdfReader.ASCIIHexDecode(b, out);
            return b;
        }
    }

    /**
     * Handles ASCIIHEXDECODE filter
     */
    private static class Filter_ASCII85DECODE implements FilterHandler{
        public byte[] decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary) throws IOException {
            ByteArrayOutputStream out = enableMemoryLimitsAwareHandler(streamDictionary);
            b = PdfReader.ASCII85Decode(b, out);
            return b;
        }
    }
    
    /**
     * Handles LZWDECODE filter
     */
    private static class Filter_LZWDECODE implements FilterHandler{
        public byte[] decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary) throws IOException {
            ByteArrayOutputStream out = enableMemoryLimitsAwareHandler(streamDictionary);
            b = PdfReader.LZWDecode(b, out);
            b = PdfReader.decodePredictor(b, decodeParams);
            return b;
        }
    }

    
    /**
     * Handles CCITTFAXDECODE filter
     */
    private static class Filter_CCITTFAXDECODE implements FilterHandler{
        public byte[] decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary) throws IOException {
            PdfNumber wn = (PdfNumber)PdfReader.getPdfObjectRelease(streamDictionary.get(PdfName.WIDTH));
            PdfNumber hn = (PdfNumber)PdfReader.getPdfObjectRelease(streamDictionary.get(PdfName.HEIGHT));
            if (wn == null || hn == null)
                throw new UnsupportedPdfException(MessageLocalization.getComposedMessage("filter.ccittfaxdecode.is.only.supported.for.images"));
            int width = wn.intValue();
            int height = hn.intValue();
            
            PdfDictionary param = decodeParams instanceof PdfDictionary ? (PdfDictionary)decodeParams : null;
            int k = 0;
            boolean blackIs1 = false;
            boolean byteAlign = false;
            if (param != null) {
                PdfNumber kn = param.getAsNumber(PdfName.K);
                if (kn != null)
                    k = kn.intValue();
                PdfBoolean bo = param.getAsBoolean(PdfName.BLACKIS1);
                if (bo != null)
                    blackIs1 = bo.booleanValue();
                bo = param.getAsBoolean(PdfName.ENCODEDBYTEALIGN);
                if (bo != null)
                    byteAlign = bo.booleanValue();
            }
            byte[] outBuf = new byte[(width + 7) / 8 * height];
            TIFFFaxDecompressor decoder = new TIFFFaxDecompressor();
            if (k == 0 || k > 0) {
                int tiffT4Options = k > 0 ? TIFFConstants.GROUP3OPT_2DENCODING : 0;
                tiffT4Options |= byteAlign ? TIFFConstants.GROUP3OPT_FILLBITS : 0;
                decoder.SetOptions(1, TIFFConstants.COMPRESSION_CCITTFAX3, tiffT4Options, 0);
                decoder.decodeRaw(outBuf, b, width, height);
                if (decoder.fails > 0) {
                    byte[] outBuf2 = new byte[(width + 7) / 8 * height];
                    int oldFails = decoder.fails;
                    decoder.SetOptions(1, TIFFConstants.COMPRESSION_CCITTRLE, tiffT4Options, 0);
                    decoder.decodeRaw(outBuf2, b, width, height);
                    if (decoder.fails < oldFails) {
                        outBuf = outBuf2;
                    }
                }
            }
            else {
                TIFFFaxDecoder deca = new TIFFFaxDecoder(1, width, height);
                deca.decodeT6(outBuf, b, 0, height, 0);
            }
            if (!blackIs1) {
                int len = outBuf.length;
                for (int t = 0; t < len; ++t) {
                    outBuf[t] ^= 0xff;
                }
            }
            b = outBuf;       
            return b;
        }
    }
    
    /**
     * A filter that doesn't modify the stream at all
     */
    private static class Filter_DoNothing implements FilterHandler{
        public byte[] decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary) throws IOException {
            return b;
        }
    }

    /**
     * Handles RUNLENGTHDECODE filter
     */
    private static class Filter_RUNLENGTHDECODE implements FilterHandler{

        public byte[] decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary) throws IOException {
         // allocate the output buffer
            ByteArrayOutputStream out = enableMemoryLimitsAwareHandler(streamDictionary);
            byte dupCount = -1;
            for(int i = 0; i < b.length; i++){
                dupCount = b[i];
                if (dupCount == -128) break; // this is implicit end of data
                
                if (dupCount >= 0 && dupCount <= 127){
                    int bytesToCopy = dupCount+1;
                    out.write(b, i, bytesToCopy);
                    i+=bytesToCopy;
                } else {
                    // make dupcount copies of the next byte
                    i++;
                    for(int j = 0; j < 1-(int)(dupCount);j++){ 
                        out.write(b[i]);
                    }
                }
            }
            return out.toByteArray();
        }
    }
    
}

⏎ com/itextpdf/text/pdf/FilterHandlers.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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⇒ 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