iText 5 itextpdf.jar Source Code

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:

✍: FYIcenter.com

com/itextpdf/text/pdf/codec/LZWCompressor.java

/*
 * Copyright 2003-2012 by Paulo Soares.
 *
 * This code was originally released in 2001 by SUN (see class
 * com.sun.media.imageio.plugins.tiff.TIFFDirectory.java)
 * using the BSD license in a specific wording. In a mail dating from
 * January 23, 2008, Brian Burkhalter (@sun.com) gave us permission
 * to use the code under the following version of the BSD license:
 *
 * Copyright (c) 2005 Sun Microsystems, Inc. All  Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met: 
 * 
 * - Redistribution of source code must retain the above copyright 
 *   notice, this  list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in 
 *   the documentation and/or other materials provided with the
 *   distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of 
 * contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any 
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL 
 * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF 
 * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR 
 * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
 * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
 * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
 * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES. 
 * 
 * You acknowledge that this software is not designed or intended for 
 * use in the design, construction, operation or maintenance of any 
 * nuclear facility. 
 *
 * $Revision$
 * $Date$
 * $State: Exp $
 */

package com.itextpdf.text.pdf.codec;

import java.io.IOException;
import java.io.OutputStream;

/**
 * Modified from original LZWCompressor to change interface to passing a
 * buffer of data to be compressed.
 * @since 5.0.2
 */
public class LZWCompressor
{
    /** base underlying code size of data being compressed 8 for TIFF, 1 to 8 for GIF **/
    int codeSize_;

    /** reserved clear code based on code size **/
    int clearCode_;

    /** reserved end of data code based on code size **/
    int endOfInfo_;

    /** current number bits output for each code **/
    int numBits_;

    /** limit at which current number of bits code size has to be increased **/
    int limit_;

    /** the prefix code which represents the predecessor string to current input point **/
    short prefix_;

    /** output destination for bit codes **/
    BitFile bf_;

    /** general purpose LZW string table **/
    LZWStringTable lzss_;

    /** modify the limits of the code values in LZW encoding due to TIFF bug / feature **/
    boolean tiffFudge_;

    /**
	 * @param out destination for compressed data
	 * @param codeSize the initial code size for the LZW compressor
	 * @param TIFF flag indicating that TIFF lzw fudge needs to be applied
	 * @exception IOException if underlying output stream error
	 **/
    public LZWCompressor(OutputStream out, int codeSize, boolean TIFF) throws IOException
    {
        bf_ = new BitFile(out, !TIFF);	// set flag for GIF as NOT tiff
        codeSize_  = codeSize;
        tiffFudge_ = TIFF;
        clearCode_ = 1 << codeSize_;
        endOfInfo_ = clearCode_ + 1;
        numBits_   = codeSize_ + 1;

        limit_ = (1 << numBits_) - 1;
        if (tiffFudge_)
            --limit_;

        prefix_ = (short)0xFFFF;
        lzss_ = new LZWStringTable();
        lzss_.ClearTable(codeSize_);
        bf_.writeBits(clearCode_, numBits_);
    }

    /**
	 * @param buf data to be compressed to output stream
	 * @exception IOException if underlying output stream error
	 **/
    public void compress(byte[] buf, int offset, int length)
        throws IOException
    {
        int idx;
        byte c;
        short index;

        int maxOffset = offset + length;
        for (idx = offset; idx < maxOffset; ++idx)
            {
                c = buf[idx];
                if ((index = lzss_.FindCharString(prefix_, c)) != -1)
                    prefix_ = index;
                else
                    {
                        bf_.writeBits(prefix_, numBits_);
                        if (lzss_.AddCharString(prefix_, c) > limit_)
                            {
                                if (numBits_ == 12)
                                    {
                                        bf_.writeBits(clearCode_, numBits_);
                                        lzss_.ClearTable(codeSize_);
                                        numBits_ = codeSize_ + 1;
                                    }
                                else
                                    ++numBits_;

                                limit_ = (1 << numBits_) - 1;
                                if (tiffFudge_)
                                    --limit_;
                            }
                        prefix_ = (short)((short)c & 0xFF);
                    }
            }
    }

    /**
	 * Indicate to compressor that no more data to go so write out
	 * any remaining buffered data.
	 *
	 * @exception IOException if underlying output stream error
	 **/
    public void flush() throws IOException
    {
        if (prefix_ != -1)
            bf_.writeBits(prefix_, numBits_);
		
        bf_.writeBits(endOfInfo_, numBits_);
        bf_.flush();
    }
}

com/itextpdf/text/pdf/codec/LZWCompressor.java

 

⇒ 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

2021-07-03, 47866👍, 0💬