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/xmp/impl/ByteBuffer.java

//Copyright (c) 2006, Adobe Systems Incorporated
//All rights reserved.
//
//        Redistribution and use in source and binary forms, with or without
//        modification, are permitted provided that the following conditions are met:
//        1. Redistributions of source code must retain the above copyright
//        notice, this list of conditions and the following disclaimer.
//        2. Redistributions 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.
//        3. All advertising materials mentioning features or use of this software
//        must display the following acknowledgement:
//        This product includes software developed by the Adobe Systems Incorporated.
//        4. Neither the name of the Adobe Systems Incorporated nor the
//        names of its contributors may be used to endorse or promote products
//        derived from this software without specific prior written permission.
//
//        THIS SOFTWARE IS PROVIDED BY ADOBE SYSTEMS INCORPORATED ''AS IS'' AND ANY
//        EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
//        WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
//        DISCLAIMED. IN NO EVENT SHALL ADOBE SYSTEMS INCORPORATED BE LIABLE FOR ANY
//        DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
//        (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
//        LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
//        ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
//        (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
//        SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//        http://www.adobe.com/devnet/xmp/library/eula-xmp-library-java.html

package com.itextpdf.xmp.impl;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;


/**
 * Byte buffer container including length of valid data.
 * 
 * @since   11.10.2006
 */
public class ByteBuffer
{
	/** */
	private byte[] buffer;
	/** */
	private int length;
	/** */
	private String encoding = null;
	

	/**
	 * @param initialCapacity the initial capacity for this buffer
	 */
	public ByteBuffer(int initialCapacity)
	{
		this.buffer = new byte[initialCapacity];
		this.length = 0;
	}

	
	/**
	 * @param buffer a byte array that will be wrapped with <code>ByteBuffer</code>.
	 */
	public ByteBuffer(byte[] buffer)
	{
		this.buffer = buffer;
		this.length = buffer.length;
	}
	
	
	/**
	 * @param buffer a byte array that will be wrapped with <code>ByteBuffer</code>.
	 * @param length the length of valid bytes in the array
	 */
	public ByteBuffer(byte[] buffer, int length)
	{
		if (length > buffer.length)
		{
			throw new ArrayIndexOutOfBoundsException("Valid length exceeds the buffer length.");
		}
		this.buffer = buffer;
		this.length = length;
	}

	
	/**
	 * Loads the stream into a buffer. 
	 * 
	 * @param in an InputStream
	 * @throws IOException If the stream cannot be read.
	 */
	public ByteBuffer(InputStream in) throws IOException
	{
		// load stream into buffer
		int chunk = 16384;
		this.length = 0;
		this.buffer = new byte[chunk];
		
		int read;
		while ((read = in.read(this.buffer, this.length, chunk)) > 0)
		{
			this.length += read;
			if (read == chunk)
			{
				ensureCapacity(length + chunk);
			}
			else
			{
				break;
			}
		}
	}	
	
	
	/**
	 * @param buffer a byte array that will be wrapped with <code>ByteBuffer</code>.
	 * @param offset the offset of the provided buffer.
	 * @param length the length of valid bytes in the array
	 */
	public ByteBuffer(byte[] buffer, int offset, int length)
	{
		if (length > buffer.length - offset)
		{
			throw new ArrayIndexOutOfBoundsException("Valid length exceeds the buffer length.");
		}
		this.buffer = new byte[length];
		System.arraycopy(buffer, offset, this.buffer, 0, length);
		this.length = length;
	}
	
	
	/**
	 * @return Returns a byte stream that is limited to the valid amount of bytes.
	 */
	public InputStream getByteStream()
	{
		return new ByteArrayInputStream(buffer, 0, length);
	}
	
	
	/**
	 * @return Returns the length, that means the number of valid bytes, of the buffer;
	 * the inner byte array might be bigger than that.
	 */
	public int length()
	{
		return length;
	}


//	/**
//	 * <em>Note:</em> Only the byte up to length are valid!
//	 * @return Returns the inner byte buffer.
//	 */
//	public byte[] getBuffer()
//	{
//		return buffer;
//	}

	
	/**
	 * @param index the index to retrieve the byte from
	 * @return Returns a byte from the buffer
	 */
	public byte byteAt(int index)
	{
		if (index < length)
		{	
			return buffer[index];
		}
		else
		{
			throw new IndexOutOfBoundsException("The index exceeds the valid buffer area");
		}
	}

	
	/**
	 * @param index the index to retrieve a byte as int or char.
	 * @return Returns a byte from the buffer
	 */
	public int charAt(int index)
	{
		if (index < length)
		{	
			return buffer[index] & 0xFF;
		}
		else
		{
			throw new IndexOutOfBoundsException("The index exceeds the valid buffer area");
		}
	}
	
	
	/**
	 * Appends a byte to the buffer.
	 * @param b a byte
	 */
	public void append(byte b)
	{
		ensureCapacity(length + 1);
		buffer[length++] = b;
	}
	
	
	/**
	 * Appends a byte array or part of to the buffer.
	 * 
	 * @param bytes a byte array
	 * @param offset an offset with
	 * @param len
	 */
	public void append(byte[] bytes, int offset, int len)
	{
		ensureCapacity(length + len);
		System.arraycopy(bytes, offset, buffer, length, len);
		length += len;
	}
	
	
	/**
	 * Append a byte array to the buffer 
	 * @param bytes a byte array
	 */
	public void append(byte[] bytes)
	{
		append(bytes, 0, bytes.length);
	}
	
	
	/**
	 * Append another buffer to this buffer. 
	 * @param anotherBuffer another <code>ByteBuffer</code>
	 */
	public void append(ByteBuffer anotherBuffer)
	{
		append(anotherBuffer.buffer, 0, anotherBuffer.length); 
	}
	
	
	/**
	 * Detects the encoding of the byte buffer, stores and returns it. 
	 * Only UTF-8, UTF-16LE/BE and UTF-32LE/BE are recognized.
	 * <em>Note:</em> UTF-32 flavors are not supported by Java, the XML-parser will complain.
	 *
	 * @return Returns the encoding string.
	 */
	public String getEncoding()
	{
		if (encoding == null)
		{	
			// needs four byte at maximum to determine encoding
			if (length < 2)
			{
				// only one byte length must be UTF-8
				encoding = "UTF-8";
			}
			else if (buffer[0] == 0)
			{
				// These cases are:
				//   00 nn -- -- - Big endian UTF-16
				//   00 00 00 nn - Big endian UTF-32
				//   00 00 FE FF - Big endian UTF 32
		
				if (length < 4  ||  buffer[1] != 0)
				{
					encoding =  "UTF-16BE";
				}
				else if ((buffer[2] & 0xFF) == 0xFE  &&  (buffer[3] & 0xFF) == 0xFF)
				{
					encoding = "UTF-32BE";
				}
				else
				{
					encoding = "UTF-32";
				}
			} 
			else if ((buffer[0] & 0xFF) < 0x80)
			{
				// These cases are:
				//   nn mm -- -- - UTF-8, includes EF BB BF case
				//   nn 00 -- -- - Little endian UTF-16
		
				if (buffer[1] != 0)
				{
					encoding = "UTF-8";
				}
				else if (length < 4  ||  buffer[2] != 0) 
				{
					encoding = "UTF-16LE";
				}
				else
				{
					encoding = "UTF-32LE";
				}
			}
			else
			{
				// These cases are:
				//   EF BB BF -- - UTF-8
				//   FE FF -- -- - Big endian UTF-16
				//   FF FE 00 00 - Little endian UTF-32
				//   FF FE -- -- - Little endian UTF-16
		
				if ((buffer[0] & 0xFF) == 0xEF)
				{
					encoding = "UTF-8";
				}
				else if ((buffer[0] & 0xFF) == 0xFE)
				{
					encoding = "UTF-16"; // in fact BE 
				}
				else if (length < 4  ||  buffer[2] != 0)
				{
					encoding = "UTF-16"; // in fact LE
				}
				else
				{
					encoding = "UTF-32"; // in fact LE
				}
			}
		}
		
		return encoding;
	}
	
	
	/**
	 * Ensures the requested capacity by increasing the buffer size when the
	 * current length is exceeded.
	 * 
	 * @param requestedLength requested new buffer length
	 */
	private void ensureCapacity(int requestedLength)
	{
		if (requestedLength > buffer.length)
		{
			byte[] oldBuf = buffer;
			buffer = new byte[oldBuf.length * 2];
			System.arraycopy(oldBuf, 0, buffer, 0, oldBuf.length);
		}
	}
}

⏎ com/itextpdf/xmp/impl/ByteBuffer.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 

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