/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2014 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package io.undertow.websockets.core.protocol.version07;

import io.undertow.UndertowLogger;

import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;


Encodes and decodes to and from Base64 notation.


Homepage: http://iharder.net/base64.


Example:

String encoded = Base64.encode( myByteArray ); 

byte[] myByteArray = Base64.decode( encoded );

The options parameter, which appears in a few places, is used to pass several pieces of information to the encoder.
In the "higher level" methods such as encodeBytes( bytes, options ) the options parameter can be used to indicate such things
as first gzipping the bytes before encoding them, not inserting linefeeds, and encoding using the URL-safe and Ordered
dialects.


Note, according to RFC3548, Section 2.1, implementations should not add
line feeds unless explicitly told to do so. I've got Base64 set to this behavior now, although earlier versions broke lines
by default.


The constants defined in Base64 can be OR-ed together to combine options, so you might make a call like this:

String encoded = Base64.encodeBytes( mybytes, Base64.GZIP | Base64.DO_BREAK_LINES );

to compress the data before encoding it and then making the output have newline characters.


Also...

String encoded = Base64.encodeBytes( crazyString.getBytes() );

Change Log:


v2.3.7 - Fixed subtle bug when base 64 input stream contained the value 01111111, which is an invalid base 64 character
but should not throw an ArrayIndexOutOfBoundsException either. Led to discovery of mishandling (or potential for better
handling) of other bad input characters. You should now get an IOException if you try decoding something that has bad
characters in it.
v2.3.6 - Fixed bug when breaking lines and the final byte of the encoded string ended in the last column; the buffer was
not properly shrunk and contained an extra (null) byte that made it into the string.
v2.3.5 - Fixed bug in encodeFromFile where estimated buffer size was wrong for files of size 31, 34, and 37 bytes.
v2.3.4 - Fixed bug when working with gzipped streams whereby flushing the Base64.OutputStream closed the Base64 encoding (by padding with equals signs) too soon. Also added an option to suppress the automatic decoding of gzipped streams. Also added experimental support for specifying a class loader when using the decodeToObject(String, int, ClassLoader) method.
v2.3.3 - Changed default char encoding to US-ASCII which reduces the internal Java footprint with its CharEncoders and so
forth. Fixed some javadocs that were inconsistent. Removed imports and specified things like java.io.IOException explicitly
inline.
v2.3.2 - Reduced memory footprint! Finally refined the "guessing" of how big the final encoded data will be so that the code doesn't have to create two output arrays: an oversized initial one and then a final, exact-sized one. Big win when using the encodeBytesToBytes(byte[]) family of methods (and not using the gzip options which uses a different mechanism with streams and stuff).
v2.3.1 - Added encodeBytesToBytes(byte[], int, int, int) and some similar helper methods to be more efficient with memory by not returning a String but just a byte array.
v2.3 - This is not a drop-in replacement! This is two years of comments and bug fixes queued up and
finally executed. Thanks to everyone who sent me stuff, and I'm sorry I wasn't able to distribute your fixes to everyone
else. Much bad coding was cleaned up including throwing exceptions where necessary instead of returning null values or
something similar. Here are some changes that may affect you:

Does not break lines, by default. This is to keep in compliance with RFC3548.
Throws exceptions instead of returning null values. Because some operations (especially those that may permit
the GZIP option) use IO streams, there is a possibility of an java.io.IOException being thrown. After some discussion and
thought, I've changed the behavior of the methods to throw java.io.IOExceptions rather than return null if ever there's an
error. I think this is more appropriate, though it will require some changes to your code. Sorry, it should have been done
this way to begin with.
Removed all references to System.out, System.err, and the like. Shame on me. All I can say is sorry they were
ever there.
Throws NullPointerExceptions and IllegalArgumentExceptions as needed such as when passed arrays are null or
offsets are invalid.
Cleaned up as much javadoc as I could to avoid any javadoc warnings. This was especially annoying before for people who
were thorough in their own projects and then had gobs of javadoc warnings on this file.

v2.2.1 - Fixed bug using URL_SAFE and ORDERED encodings. Fixed bug when using very small files (~< 40 bytes).
v2.2 - Added some helper methods for encoding/decoding directly from one file to the next. Also added a main() method to
support command line encoding/decoding from one file to the next. Also added these Base64 dialects:

The default is RFC3548 format.
Calling Base64.setFormat(Base64.BASE64_FORMAT.URLSAFE_FORMAT) generates URL and file name friendly format as described in
Section 4 of RFC3548. http://www.faqs.org/rfcs/rfc3548.html
Calling Base64.setFormat(Base64.BASE64_FORMAT.ORDERED_FORMAT) generates URL and file name friendly format that preserves
lexical ordering as described in http://www.faqs.org/qa/rfcc-1940.html

Special thanks to Jim Kellerman at http://www.powerset.com/ for contributing the new
Base64 dialects.
v2.1 - Cleaned up javadoc comments and unused variables and methods. Added some convenience methods for reading and
writing to and from files.
v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems with other encodings (like EBCDIC).
v2.0.1 - Fixed an error when decoding a single byte, that is, when the encoded data was a single byte.
v2.0 - I got rid of methods that used booleans to set options. Now everything is more consolidated and cleaner. The code
now detects when data that's being decoded is gzip-compressed and will decompress it automatically. Generally things are
cleaner. You'll probably have to change some method calls that you were making to support the new options format (
ints that you "OR" together).
v1.5.1 - Fixed bug when decompressing and decoding to a byte[] using decode( String s, boolean gzipCompressed ).
Added the ability to "suspend" encoding in the Output Stream so you can turn on and off the encoding if you need to embed
base64 data in an otherwise "normal" stream (like an XML file).
v1.5 - Output stream passes on flush() command but doesn't do anything itself. This helps when using GZIP streams. Added
the ability to GZip-compress objects before encoding them.
v1.4 - Added helper methods to read/write files.
v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.
v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input stream where last buffer being read, if not
completely full, was not returned.
v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.
v1.3.3 - Fixed I/O streams which were totally messed up.


I am placing this code in the Public Domain. Do with it as you will. This software comes with no guarantees or warranties but
with plenty of well-wishing instead! Please visit http://iharder.net/base64
periodically to check for updates or to contribute improvements.

Author:
Robert Harder, rob@iharder.net
Version:
2.3.7/**
 * <p>
 * Encodes and decodes to and from Base64 notation.
 * </p>
 * <p>
 * Homepage: <a href="http://iharder.net/base64">http://iharder.net/base64</a>.
 * </p>
 *
 * <p>
 * Example:
 * </p>
 *
 * <code>String encoded = Base64.encode( myByteArray );</code> <br />
 * <code>byte[] myByteArray = Base64.decode( encoded );</code>
 *
 * <p>
 * The <tt>options</tt> parameter, which appears in a few places, is used to pass several pieces of information to the encoder.
 * In the "higher level" methods such as encodeBytes( bytes, options ) the options parameter can be used to indicate such things
 * as first gzipping the bytes before encoding them, not inserting linefeeds, and encoding using the URL-safe and Ordered
 * dialects.
 * </p>
 *
 * <p>
 * Note, according to <a href="http://www.faqs.org/rfcs/rfc3548.html">RFC3548</a>, Section 2.1, implementations should not add
 * line feeds unless explicitly told to do so. I've got Base64 set to this behavior now, although earlier versions broke lines
 * by default.
 * </p>
 *
 * <p>
 * The constants defined in Base64 can be OR-ed together to combine options, so you might make a call like this:
 * </p>
 *
 * <code>String encoded = Base64.encodeBytes( mybytes, Base64.GZIP | Base64.DO_BREAK_LINES );</code>
 * <p>
 * to compress the data before encoding it and then making the output have newline characters.
 * </p>
 * <p>
 * Also...
 * </p>
 * <code>String encoded = Base64.encodeBytes( crazyString.getBytes() );</code>
 *
 *
 *
 * <p>
 * Change Log:
 * </p>
 * <ul>
 * <li>v2.3.7 - Fixed subtle bug when base 64 input stream contained the value 01111111, which is an invalid base 64 character
 * but should not throw an ArrayIndexOutOfBoundsException either. Led to discovery of mishandling (or potential for better
 * handling) of other bad input characters. You should now get an IOException if you try decoding something that has bad
 * characters in it.</li>
 * <li>v2.3.6 - Fixed bug when breaking lines and the final byte of the encoded string ended in the last column; the buffer was
 * not properly shrunk and contained an extra (null) byte that made it into the string.</li>
 * <li>v2.3.5 - Fixed bug in {@link #encodeFromFile} where estimated buffer size was wrong for files of size 31, 34, and 37
 * bytes.</li>
 * <li>v2.3.4 - Fixed bug when working with gzipped streams whereby flushing the Base64.OutputStream closed the Base64 encoding
 * (by padding with equals signs) too soon. Also added an option to suppress the automatic decoding of gzipped streams. Also
 * added experimental support for specifying a class loader when using the
 * {@link #decodeToObject(String, int, ClassLoader)} method.</li>
 * <li>v2.3.3 - Changed default char encoding to US-ASCII which reduces the internal Java footprint with its CharEncoders and so
 * forth. Fixed some javadocs that were inconsistent. Removed imports and specified things like java.io.IOException explicitly
 * inline.</li>
 * <li>v2.3.2 - Reduced memory footprint! Finally refined the "guessing" of how big the final encoded data will be so that the
 * code doesn't have to create two output arrays: an oversized initial one and then a final, exact-sized one. Big win when using
 * the {@link #encodeBytesToBytes(byte[])} family of methods (and not using the gzip options which uses a different mechanism
 * with streams and stuff).</li>
 * <li>v2.3.1 - Added {@link #encodeBytesToBytes(byte[], int, int, int)} and some similar helper methods to be more efficient
 * with memory by not returning a String but just a byte array.</li>
 * <li>v2.3 - <strong>This is not a drop-in replacement!</strong> This is two years of comments and bug fixes queued up and
 * finally executed. Thanks to everyone who sent me stuff, and I'm sorry I wasn't able to distribute your fixes to everyone
 * else. Much bad coding was cleaned up including throwing exceptions where necessary instead of returning null values or
 * something similar. Here are some changes that may affect you:
 * <ul>
 * <li><em>Does not break lines, by default.</em> This is to keep in compliance with <a
 * href="http://www.faqs.org/rfcs/rfc3548.html">RFC3548</a>.</li>
 * <li><em>Throws exceptions instead of returning null values.</em> Because some operations (especially those that may permit
 * the GZIP option) use IO streams, there is a possibility of an java.io.IOException being thrown. After some discussion and
 * thought, I've changed the behavior of the methods to throw java.io.IOExceptions rather than return null if ever there's an
 * error. I think this is more appropriate, though it will require some changes to your code. Sorry, it should have been done
 * this way to begin with.</li>
 * <li><em>Removed all references to System.out, System.err, and the like.</em> Shame on me. All I can say is sorry they were
 * ever there.</li>
 * <li><em>Throws NullPointerExceptions and IllegalArgumentExceptions</em> as needed such as when passed arrays are null or
 * offsets are invalid.</li>
 * <li>Cleaned up as much javadoc as I could to avoid any javadoc warnings. This was especially annoying before for people who
 * were thorough in their own projects and then had gobs of javadoc warnings on this file.</li>
 * </ul>
 * <li>v2.2.1 - Fixed bug using URL_SAFE and ORDERED encodings. Fixed bug when using very small files (~&lt; 40 bytes).</li>
 * <li>v2.2 - Added some helper methods for encoding/decoding directly from one file to the next. Also added a main() method to
 * support command line encoding/decoding from one file to the next. Also added these Base64 dialects:
 * <ol>
 * <li>The default is RFC3548 format.</li>
 * <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.URLSAFE_FORMAT) generates URL and file name friendly format as described in
 * Section 4 of RFC3548. http://www.faqs.org/rfcs/rfc3548.html</li>
 * <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.ORDERED_FORMAT) generates URL and file name friendly format that preserves
 * lexical ordering as described in http://www.faqs.org/qa/rfcc-1940.html</li>
 * </ol>
 * Special thanks to Jim Kellerman at <a href="http://www.powerset.com/">http://www.powerset.com/</a> for contributing the new
 * Base64 dialects.</li>
 *
 * <li>v2.1 - Cleaned up javadoc comments and unused variables and methods. Added some convenience methods for reading and
 * writing to and from files.</li>
 * <li>v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems with other encodings (like EBCDIC).</li>
 * <li>v2.0.1 - Fixed an error when decoding a single byte, that is, when the encoded data was a single byte.</li>
 * <li>v2.0 - I got rid of methods that used booleans to set options. Now everything is more consolidated and cleaner. The code
 * now detects when data that's being decoded is gzip-compressed and will decompress it automatically. Generally things are
 * cleaner. You'll probably have to change some method calls that you were making to support the new options format (
 * <tt>int</tt>s that you "OR" together).</li>
 * <li>v1.5.1 - Fixed bug when decompressing and decoding to a byte[] using <tt>decode( String s, boolean gzipCompressed )</tt>.
 * Added the ability to "suspend" encoding in the Output Stream so you can turn on and off the encoding if you need to embed
 * base64 data in an otherwise "normal" stream (like an XML file).</li>
 * <li>v1.5 - Output stream passes on flush() command but doesn't do anything itself. This helps when using GZIP streams. Added
 * the ability to GZip-compress objects before encoding them.</li>
 * <li>v1.4 - Added helper methods to read/write files.</li>
 * <li>v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.</li>
 * <li>v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input stream where last buffer being read, if not
 * completely full, was not returned.</li>
 * <li>v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.</li>
 * <li>v1.3.3 - Fixed I/O streams which were totally messed up.</li>
 * </ul>
 *
 * <p>
 * I am placing this code in the Public Domain. Do with it as you will. This software comes with no guarantees or warranties but
 * with plenty of well-wishing instead! Please visit <a href="http://iharder.net/base64">http://iharder.net/base64</a>
 * periodically to check for updates or to contribute improvements.
 * </p>
 *
 * @author Robert Harder
 * @author rob@iharder.net
 * @version 2.3.7
 */
class Base64 {

    /* ******** P U B L I C F I E L D S ******** */

    
No options specified. Value is zero. /** No options specified. Value is zero. */
    public static final int NO_OPTIONS = 0;

    
Specify encoding in first bit. Value is one. /** Specify encoding in first bit. Value is one. */
    public static final int ENCODE = 1;

    
Specify decoding in first bit. Value is zero. /** Specify decoding in first bit. Value is zero. */
    public static final int DECODE = 0;

    
Specify that data should be gzip-compressed in second bit. Value is two. /** Specify that data should be gzip-compressed in second bit. Value is two. */
    public static final int GZIP = 2;

    
Specify that gzipped data should not be automatically gunzipped. /** Specify that gzipped data should <em>not</em> be automatically gunzipped. */
    public static final int DONT_GUNZIP = 4;

    
Do break lines when encoding. Value is 8. /** Do break lines when encoding. Value is 8. */
    public static final int DO_BREAK_LINES = 8;

    
Encode using Base64-like encoding that is URL- and Filename-safe as described in Section 4 of RFC3548: http://www.faqs.org/rfcs/rfc3548.html. It is important to note that data
encoded this way is not officially valid Base64, or at the very least should not be called Base64 without also
specifying that is was encoded using the URL- and Filename-safe dialect.
/**
     * Encode using Base64-like encoding that is URL- and Filename-safe as described in Section 4 of RFC3548: <a
     * href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>. It is important to note that data
     * encoded this way is <em>not</em> officially valid Base64, or at the very least should not be called Base64 without also
     * specifying that is was encoded using the URL- and Filename-safe dialect.
     */
    public static final int URL_SAFE = 16;

    
Encode using the special "ordered" dialect of Base64 described here: http://www.faqs.org/qa/rfcc-1940.html.
/**
     * Encode using the special "ordered" dialect of Base64 described here: <a
     * href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
     */
    public static final int ORDERED = 32;

    /* ******** P R I V A T E F I E L D S ******** */

    
Maximum line length (76) of Base64 output. /** Maximum line length (76) of Base64 output. */
    private static final int MAX_LINE_LENGTH = 76;

    
The equals sign (=) as a byte. /** The equals sign (=) as a byte. */
    private static final byte EQUALS_SIGN = (byte) '=';

    
The new line character (\n) as a byte. /** The new line character (\n) as a byte. */
    private static final byte NEW_LINE = (byte) '\n';

    private static final byte WHITE_SPACE_ENC = -5; // Indicates white space in encoding
    private static final byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in encoding

    /* ******** S T A N D A R D B A S E 6 4 A L P H A B E T ******** */

    
The 64 valid Base64 values. /** The 64 valid Base64 values. */
    /* Host platform me be something funny like EBCDIC, so we hardcode these values. */
    private static final byte[] _STANDARD_ALPHABET = { (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F',
            (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O',
            (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X',
            (byte) 'Y', (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g',
            (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p',
            (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y',
            (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7',
            (byte) '8', (byte) '9', (byte) '+', (byte) '/' };

    
Translates a Base64 value to either its 6-bit reconstruction value or a negative number indicating some other meaning.
/**
     * Translates a Base64 value to either its 6-bit reconstruction value or a negative number indicating some other meaning.
     **/
    private static final byte[] _STANDARD_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8
            -5, -5, // Whitespace: Tab and Linefeed
            -9, -9, // Decimal 11 - 12
            -5, // Whitespace: Carriage Return
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
            -9, -9, -9, -9, -9, // Decimal 27 - 31
            -5, // Whitespace: Space
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
            62, // Plus sign at decimal 43
            -9, -9, -9, // Decimal 44 - 46
            63, // Slash at decimal 47
            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
            -9, -9, -9, // Decimal 58 - 60
            -1, // Equals sign at decimal 61
            -9, -9, -9, // Decimal 62 - 64
            0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N'
            14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z'
            -9, -9, -9, -9, -9, -9, // Decimal 91 - 96
            26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm'
            39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z'
            -9, -9, -9, -9, -9 // Decimal 123 - 127
            , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
    };

    /* ******** U R L S A F E B A S E 6 4 A L P H A B E T ******** */

    
Used in the URL- and Filename-safe dialect described in Section 4 of RFC3548: http://www.faqs.org/rfcs/rfc3548.html. Notice that the last two bytes
become "hyphen" and "underscore" instead of "plus" and "slash."
/**
     * Used in the URL- and Filename-safe dialect described in Section 4 of RFC3548: <a
     * href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>. Notice that the last two bytes
     * become "hyphen" and "underscore" instead of "plus" and "slash."
     */
    private static final byte[] _URL_SAFE_ALPHABET = { (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F',
            (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O',
            (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W', (byte) 'X',
            (byte) 'Y', (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g',
            (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p',
            (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y',
            (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7',
            (byte) '8', (byte) '9', (byte) '-', (byte) '_' };

    
Used in decoding URL- and Filename-safe dialects of Base64.
/**
     * Used in decoding URL- and Filename-safe dialects of Base64.
     */
    private static final byte[] _URL_SAFE_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8
            -5, -5, // Whitespace: Tab and Linefeed
            -9, -9, // Decimal 11 - 12
            -5, // Whitespace: Carriage Return
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
            -9, -9, -9, -9, -9, // Decimal 27 - 31
            -5, // Whitespace: Space
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
            -9, // Plus sign at decimal 43
            -9, // Decimal 44
            62, // Minus sign at decimal 45
            -9, // Decimal 46
            -9, // Slash at decimal 47
            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
            -9, -9, -9, // Decimal 58 - 60
            -1, // Equals sign at decimal 61
            -9, -9, -9, // Decimal 62 - 64
            0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through 'N'
            14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O' through 'Z'
            -9, -9, -9, -9, // Decimal 91 - 94
            63, // Underscore at decimal 95
            -9, // Decimal 96
            26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a' through 'm'
            39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n' through 'z'
            -9, -9, -9, -9, -9 // Decimal 123 - 127
            , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
    };

    /* ******** O R D E R E D B A S E 6 4 A L P H A B E T ******** */

    
I don't get the point of this technique, but someone requested it, and it is described here: http://www.faqs.org/qa/rfcc-1940.html.
/**
     * I don't get the point of this technique, but someone requested it, and it is described here: <a
     * href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
     */
    private static final byte[] _ORDERED_ALPHABET = { (byte) '-', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4',
            (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D',
            (byte) 'E', (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M',
            (byte) 'N', (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V',
            (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) '_', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd',
            (byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm',
            (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v',
            (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z' };

    
Used in decoding the "ordered" dialect of Base64.
/**
     * Used in decoding the "ordered" dialect of Base64.
     */
    private static final byte[] _ORDERED_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 0 - 8
            -5, -5, // Whitespace: Tab and Linefeed
            -9, -9, // Decimal 11 - 12
            -5, // Whitespace: Carriage Return
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 - 26
            -9, -9, -9, -9, -9, // Decimal 27 - 31
            -5, // Whitespace: Space
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
            -9, // Plus sign at decimal 43
            -9, // Decimal 44
            0, // Minus sign at decimal 45
            -9, // Decimal 46
            -9, // Slash at decimal 47
            1, 2, 3, 4, 5, 6, 7, 8, 9, 10, // Numbers zero through nine
            -9, -9, -9, // Decimal 58 - 60
            -1, // Equals sign at decimal 61
            -9, -9, -9, // Decimal 62 - 64
            11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, // Letters 'A' through 'M'
            24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, // Letters 'N' through 'Z'
            -9, -9, -9, -9, // Decimal 91 - 94
            37, // Underscore at decimal 95
            -9, // Decimal 96
            38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, // Letters 'a' through 'm'
            51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, // Letters 'n' through 'z'
            -9, -9, -9, -9, -9 // Decimal 123 - 127
            , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 - 139
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 - 152
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 - 165
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 - 178
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 - 191
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 - 204
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 - 217
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 - 230
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 - 243
            -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
    };

    /* ******** D E T E R M I N E W H I C H A L H A B E T ******** */

    
Returns one of the _SOMETHING_ALPHABET byte arrays depending on the options specified. It's possible, though silly, to
specify ORDERED and URLSAFE in which case one of them will be picked, though there is no guarantee as to which one
will be picked.
/**
     * Returns one of the _SOMETHING_ALPHABET byte arrays depending on the options specified. It's possible, though silly, to
     * specify ORDERED <b>and</b> URLSAFE in which case one of them will be picked, though there is no guarantee as to which one
     * will be picked.
     */
    private static byte[] getAlphabet(int options) {
        if ((options & URL_SAFE) == URL_SAFE) {
            return _URL_SAFE_ALPHABET;
        } else if ((options & ORDERED) == ORDERED) {
            return _ORDERED_ALPHABET;
        } else {
            return _STANDARD_ALPHABET;
        }
    } // end getAlphabet

    
Returns one of the _SOMETHING_DECODABET byte arrays depending on the options specified. It's possible, though silly, to
specify ORDERED and URL_SAFE in which case one of them will be picked, though there is no guarantee as to which one will
be picked.
/**
     * Returns one of the _SOMETHING_DECODABET byte arrays depending on the options specified. It's possible, though silly, to
     * specify ORDERED and URL_SAFE in which case one of them will be picked, though there is no guarantee as to which one will
     * be picked.
     */
    private static byte[] getDecodabet(int options) {
        if ((options & URL_SAFE) == URL_SAFE) {
            return _URL_SAFE_DECODABET;
        } else if ((options & ORDERED) == ORDERED) {
            return _ORDERED_DECODABET;
        } else {
            return _STANDARD_DECODABET;
        }
    } // end getAlphabet

    
Defeats instantiation. /** Defeats instantiation. */
    private Base64() {
    }

    /* ******** E N C O D I N G M E T H O D S ******** */

    
Encodes up to the first three bytes of array threeBytes and returns a four-byte array in Base64 notation. The
actual number of significant bytes in your array is given by numSigBytes. The array threeBytes
needs only be as big as numSigBytes. Code can reuse a byte array by passing a four-byte array as
b4.
Params:
b4 – A reusable byte array to reduce array instantiation
threeBytes – the array to convert
numSigBytes – the number of significant bytes in your array
Returns:
four byte array in Base64 notation.
Since:
1.5.1/**
     * Encodes up to the first three bytes of array <var>threeBytes</var> and returns a four-byte array in Base64 notation. The
     * actual number of significant bytes in your array is given by <var>numSigBytes</var>. The array <var>threeBytes</var>
     * needs only be as big as <var>numSigBytes</var>. Code can reuse a byte array by passing a four-byte array as
     * <var>b4</var>.
     *
     * @param b4 A reusable byte array to reduce array instantiation
     * @param threeBytes the array to convert
     * @param numSigBytes the number of significant bytes in your array
     * @return four byte array in Base64 notation.
     * @since 1.5.1
     */
    private static byte[] encode3to4(byte[] b4, byte[] threeBytes, int numSigBytes, int options) {
        encode3to4(threeBytes, 0, numSigBytes, b4, 0, options);
        return b4;
    } // end encode3to4

    

Encodes up to three bytes of the array source and writes the resulting four Base64 bytes to
destination. The source and destination arrays can be manipulated anywhere along their length by specifying
srcOffset and destOffset. This method does not check to make sure your arrays are large enough to
accomodate srcOffset + 3 for the source array or destOffset + 4 for the
destination array. The actual number of significant bytes in your array is given by numSigBytes.


This is the lowest level of the encoding methods with all possible parameters.

Params:
source – the array to convert
srcOffset – the index where conversion begins
numSigBytes – the number of significant bytes in your array
destination – the array to hold the conversion
destOffset – the index where output will be put
Returns:
the destination array
Since:
1.3/**
     * <p>
     * Encodes up to three bytes of the array <var>source</var> and writes the resulting four Base64 bytes to
     * <var>destination</var>. The source and destination arrays can be manipulated anywhere along their length by specifying
     * <var>srcOffset</var> and <var>destOffset</var>. This method does not check to make sure your arrays are large enough to
     * accomodate <var>srcOffset</var> + 3 for the <var>source</var> array or <var>destOffset</var> + 4 for the
     * <var>destination</var> array. The actual number of significant bytes in your array is given by <var>numSigBytes</var>.
     * </p>
     * <p>
     * This is the lowest level of the encoding methods with all possible parameters.
     * </p>
     *
     * @param source the array to convert
     * @param srcOffset the index where conversion begins
     * @param numSigBytes the number of significant bytes in your array
     * @param destination the array to hold the conversion
     * @param destOffset the index where output will be put
     * @return the <var>destination</var> array
     * @since 1.3
     */
    private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset,
            int options) {

        byte[] ALPHABET = getAlphabet(options);

        // 1 2 3
        // 01234567890123456789012345678901 Bit position
        // --------000000001111111122222222 Array position from threeBytes
        // --------| || || || | Six bit groups to index ALPHABET
        // >>18 >>12 >> 6 >> 0 Right shift necessary
        // 0x3f 0x3f 0x3f Additional AND

        // Create buffer with zero-padding if there are only one or two
        // significant bytes passed in the array.
        // We have to shift left 24 in order to flush out the 1's that appear
        // when Java treats a value as negative that is cast from a byte to an int.
        int inBuff = (numSigBytes > 0 ? ((source[srcOffset] << 24) >>> 8) : 0)
                | (numSigBytes > 1 ? ((source[srcOffset + 1] << 24) >>> 16) : 0)
                | (numSigBytes > 2 ? ((source[srcOffset + 2] << 24) >>> 24) : 0);

        switch (numSigBytes) {
            case 3:
                destination[destOffset] = ALPHABET[(inBuff >>> 18)];
                destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
                destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
                destination[destOffset + 3] = ALPHABET[(inBuff) & 0x3f];
                return destination;

            case 2:
                destination[destOffset] = ALPHABET[(inBuff >>> 18)];
                destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
                destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
                destination[destOffset + 3] = EQUALS_SIGN;
                return destination;

            case 1:
                destination[destOffset] = ALPHABET[(inBuff >>> 18)];
                destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
                destination[destOffset + 2] = EQUALS_SIGN;
                destination[destOffset + 3] = EQUALS_SIGN;
                return destination;

            default:
                return destination;
        } // end switch
    } // end encode3to4

    
Performs Base64 encoding on the raw ByteBuffer, writing it to the encoded ByteBuffer. This is an experimental feature. Currently it does not pass along any options (such as DO_BREAK_LINES or GZIP. 
Params:
raw – input buffer
encoded – output buffer
Since:
2.3/**
     * Performs Base64 encoding on the <code>raw</code> ByteBuffer, writing it to the <code>encoded</code> ByteBuffer. This is
     * an experimental feature. Currently it does not pass along any options (such as {@link #DO_BREAK_LINES} or {@link #GZIP}.
     *
     * @param raw input buffer
     * @param encoded output buffer
     * @since 2.3
     */
    public static void encode(java.nio.ByteBuffer raw, java.nio.ByteBuffer encoded) {
        byte[] raw3 = new byte[3];
        byte[] enc4 = new byte[4];

        while (raw.hasRemaining()) {
            int rem = Math.min(3, raw.remaining());
            raw.get(raw3, 0, rem);
            Base64.encode3to4(enc4, raw3, rem, Base64.NO_OPTIONS);
            encoded.put(enc4);
        } // end input remaining
    }

    
Performs Base64 encoding on the raw ByteBuffer, writing it to the encoded CharBuffer. This is an experimental feature. Currently it does not pass along any options (such as DO_BREAK_LINES or GZIP. 
Params:
raw – input buffer
encoded – output buffer
Since:
2.3/**
     * Performs Base64 encoding on the <code>raw</code> ByteBuffer, writing it to the <code>encoded</code> CharBuffer. This is
     * an experimental feature. Currently it does not pass along any options (such as {@link #DO_BREAK_LINES} or {@link #GZIP}.
     *
     * @param raw input buffer
     * @param encoded output buffer
     * @since 2.3
     */
    public static void encode(java.nio.ByteBuffer raw, java.nio.CharBuffer encoded) {
        byte[] raw3 = new byte[3];
        byte[] enc4 = new byte[4];

        while (raw.hasRemaining()) {
            int rem = Math.min(3, raw.remaining());
            raw.get(raw3, 0, rem);
            Base64.encode3to4(enc4, raw3, rem, Base64.NO_OPTIONS);
            for (int i = 0; i < 4; i++) {
                encoded.put((char) (enc4[i] & 0xFF));
            }
        } // end input remaining
    }

    
Serializes an object and returns the Base64-encoded version of that serialized object.

As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException.
This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor
way to handle it.

The object is not GZip-compressed before being encoded.
Params:
serializableObject – The object to encode
Throws:
IOException – if there is an error
NullPointerException – if serializedObject is null
Returns:
The Base64-encoded object
Since:
1.4/**
     * Serializes an object and returns the Base64-encoded version of that serialized object.
     *
     * <p>
     * As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException.
     * <b>This is new to v2.3!</b> In earlier versions, it just returned a null value, but in retrospect that's a pretty poor
     * way to handle it.
     * </p>
     *
     * The object is not GZip-compressed before being encoded.
     *
     * @param serializableObject The object to encode
     * @return The Base64-encoded object
     * @throws java.io.IOException if there is an error
     * @throws NullPointerException if serializedObject is null
     * @since 1.4
     */
    public static String encodeObject(java.io.Serializable serializableObject) throws java.io.IOException {
        return encodeObject(serializableObject, NO_OPTIONS);
    } // end encodeObject

    
Serializes an object and returns the Base64-encoded version of that serialized object.

As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException.
This is new to v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor
way to handle it.

The object is not GZip-compressed before being encoded.

Example options:
  GZIP: gzip-compresses object before encoding it.
  DO_BREAK_LINES: break lines at 76 characters


Example: encodeObject( myObj, Base64.GZIP ) or

Example: encodeObject( myObj, Base64.GZIP | Base64.DO_BREAK_LINES )
Params:
serializableObject – The object to encode
options – Specified options
Throws:
IOException – if there is an error
See Also:
GZIP
DO_BREAK_LINES
Returns:
The Base64-encoded object
Since:
2.0/**
     * Serializes an object and returns the Base64-encoded version of that serialized object.
     *
     * <p>
     * As of v 2.3, if the object cannot be serialized or there is another error, the method will throw an java.io.IOException.
     * <b>This is new to v2.3!</b> In earlier versions, it just returned a null value, but in retrospect that's a pretty poor
     * way to handle it.
     * </p>
     *
     * The object is not GZip-compressed before being encoded.
     * <p>
     * Example options:
     *
     * <pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DO_BREAK_LINES: break lines at 76 characters
     * </pre>
     * <p>
     * Example: <code>encodeObject( myObj, Base64.GZIP )</code> or
     * <p>
     * Example: <code>encodeObject( myObj, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
     *
     * @param serializableObject The object to encode
     * @param options Specified options
     * @return The Base64-encoded object
     * @see Base64#GZIP
     * @see Base64#DO_BREAK_LINES
     * @throws java.io.IOException if there is an error
     * @since 2.0
     */
    public static String encodeObject(java.io.Serializable serializableObject, int options) throws java.io.IOException {

        if (serializableObject == null) {
            throw new NullPointerException("Cannot serialize a null object.");
        } // end if: null

        // Streams
        java.io.ByteArrayOutputStream baos = null;
        java.io.OutputStream b64os = null;
        java.util.zip.GZIPOutputStream gzos = null;
        java.io.ObjectOutputStream oos = null;

        try {
            // ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
            baos = new java.io.ByteArrayOutputStream();
            b64os = new Base64.OutputStream(baos, ENCODE | options);
            if ((options & GZIP) != 0) {
                // Gzip
                gzos = new java.util.zip.GZIPOutputStream(b64os);
                oos = new java.io.ObjectOutputStream(gzos);
            } else {
                // Not gzipped
                oos = new java.io.ObjectOutputStream(b64os);
            }
            oos.writeObject(serializableObject);
        } // end try
        catch (java.io.IOException e) {
            // Catch it and then throw it immediately so that
            // the finally{} block is called for cleanup.
            throw e;
        } // end catch
        finally {
            try {
                oos.close();
            } catch (Exception e) {
            }
            try {
                gzos.close();
            } catch (Exception e) {
            }
            try {
                b64os.close();
            } catch (Exception e) {
            }
            try {
                baos.close();
            } catch (Exception e) {
            }
        } // end finally

        // Return value according to relevant encoding.
        return new String(baos.toByteArray(), StandardCharsets.US_ASCII);

    } // end encode

    
Encodes a byte array into Base64 notation. Does not GZip-compress data.
Params:
source – The data to convert
Throws:
NullPointerException – if source array is null
Returns:
The data in Base64-encoded form
Since:
1.4/**
     * Encodes a byte array into Base64 notation. Does not GZip-compress data.
     *
     * @param source The data to convert
     * @return The data in Base64-encoded form
     * @throws NullPointerException if source array is null
     * @since 1.4
     */
    public static String encodeBytes(byte[] source) {
        // Since we're not going to have the GZIP encoding turned on,
        // we're not going to have an java.io.IOException thrown, so
        // we should not force the user to have to catch it.
        String encoded = null;
        try {
            encoded = encodeBytes(source, 0, source.length, NO_OPTIONS);
        } catch (java.io.IOException ex) {
            assert false : ex.getMessage();
        } // end catch
        assert encoded != null;
        return encoded;
    } // end encodeBytes

    
Encodes a byte array into Base64 notation.

Example options:
  GZIP: gzip-compresses object before encoding it.
  DO_BREAK_LINES: break lines at 76 characters
    Note: Technically, this makes your encoding non-compliant.


Example: encodeBytes( myData, Base64.GZIP ) or

Example: encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )

As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. This is new to
v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

Params:
source – The data to convert
options – Specified options
Throws:
IOException – if there is an error
NullPointerException – if source array is null
See Also:
GZIP
DO_BREAK_LINES
Returns:
The Base64-encoded data as a String
Since:
2.0/**
     * Encodes a byte array into Base64 notation.
     * <p>
     * Example options:
     *
     * <pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DO_BREAK_LINES: break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     * <p>
     * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
     * <p>
     * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
     *
     *
     * <p>
     * As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. <b>This is new to
     * v2.3!</b> In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.
     * </p>
     *
     *
     * @param source The data to convert
     * @param options Specified options
     * @return The Base64-encoded data as a String
     * @see Base64#GZIP
     * @see Base64#DO_BREAK_LINES
     * @throws java.io.IOException if there is an error
     * @throws NullPointerException if source array is null
     * @since 2.0
     */
    public static String encodeBytes(byte[] source, int options) throws java.io.IOException {
        return encodeBytes(source, 0, source.length, options);
    } // end encodeBytes

    
Encodes a byte array into Base64 notation. Does not GZip-compress data.

As of v 2.3, if there is an error, the method will throw an java.io.IOException. This is new to v2.3! In earlier
versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

Params:
source – The data to convert
off – Offset in array where conversion should begin
len – Length of data to convert
Throws:
NullPointerException – if source array is null
IllegalArgumentException – if source array, offset, or length are invalid
Returns:
The Base64-encoded data as a String
Since:
1.4/**
     * Encodes a byte array into Base64 notation. Does not GZip-compress data.
     *
     * <p>
     * As of v 2.3, if there is an error, the method will throw an java.io.IOException. <b>This is new to v2.3!</b> In earlier
     * versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.
     * </p>
     *
     *
     * @param source The data to convert
     * @param off Offset in array where conversion should begin
     * @param len Length of data to convert
     * @return The Base64-encoded data as a String
     * @throws NullPointerException if source array is null
     * @throws IllegalArgumentException if source array, offset, or length are invalid
     * @since 1.4
     */
    public static String encodeBytes(byte[] source, int off, int len) {
        // Since we're not going to have the GZIP encoding turned on,
        // we're not going to have an java.io.IOException thrown, so
        // we should not force the user to have to catch it.
        String encoded = null;
        try {
            encoded = encodeBytes(source, off, len, NO_OPTIONS);
        } catch (java.io.IOException ex) {
            assert false : ex.getMessage();
        } // end catch
        assert encoded != null;
        return encoded;
    } // end encodeBytes

    
Encodes a byte array into Base64 notation.

Example options:
  GZIP: gzip-compresses object before encoding it.
  DO_BREAK_LINES: break lines at 76 characters
    Note: Technically, this makes your encoding non-compliant.


Example: encodeBytes( myData, Base64.GZIP ) or

Example: encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )

As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. This is new to
v2.3! In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.

Params:
source – The data to convert
off – Offset in array where conversion should begin
len – Length of data to convert
options – Specified options
Throws:
IOException – if there is an error
NullPointerException – if source array is null
IllegalArgumentException – if source array, offset, or length are invalid
See Also:
GZIP
DO_BREAK_LINES
Returns:
The Base64-encoded data as a String
Since:
2.0/**
     * Encodes a byte array into Base64 notation.
     * <p>
     * Example options:
     *
     * <pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DO_BREAK_LINES: break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     * <p>
     * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
     * <p>
     * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
     *
     *
     * <p>
     * As of v 2.3, if there is an error with the GZIP stream, the method will throw an java.io.IOException. <b>This is new to
     * v2.3!</b> In earlier versions, it just returned a null value, but in retrospect that's a pretty poor way to handle it.
     * </p>
     *
     *
     * @param source The data to convert
     * @param off Offset in array where conversion should begin
     * @param len Length of data to convert
     * @param options Specified options
     * @return The Base64-encoded data as a String
     * @see Base64#GZIP
     * @see Base64#DO_BREAK_LINES
     * @throws java.io.IOException if there is an error
     * @throws NullPointerException if source array is null
     * @throws IllegalArgumentException if source array, offset, or length are invalid
     * @since 2.0
     */
    public static String encodeBytes(byte[] source, int off, int len, int options) throws java.io.IOException {
        byte[] encoded = encodeBytesToBytes(source, off, len, options);

        // Return value according to relevant encoding.
        return new String(encoded, StandardCharsets.US_ASCII);

    } // end encodeBytes

    
Similar to encodeBytes(byte[]) but returns a byte array instead of instantiating a String. This is more efficient if you're working with I/O streams and have large data sets to encode. 
Params:
source – The data to convert
Throws:
NullPointerException – if source array is null
Returns:
The Base64-encoded data as a byte[] (of ASCII characters)
Since:
2.3.1/**
     * Similar to {@link #encodeBytes(byte[])} but returns a byte array instead of instantiating a String. This is more
     * efficient if you're working with I/O streams and have large data sets to encode.
     *
     *
     * @param source The data to convert
     * @return The Base64-encoded data as a byte[] (of ASCII characters)
     * @throws NullPointerException if source array is null
     * @since 2.3.1
     */
    public static byte[] encodeBytesToBytes(byte[] source) {
        byte[] encoded = null;
        try {
            encoded = encodeBytesToBytes(source, 0, source.length, Base64.NO_OPTIONS);
        } catch (java.io.IOException ex) {
            assert false : "IOExceptions only come from GZipping, which is turned off: " + ex.getMessage();
        }
        return encoded;
    }

    
Similar to encodeBytes(byte[], int, int, int) but returns a byte array instead of instantiating a String. This is more efficient if you're working with I/O streams and have large data sets to encode. 
Params:
source – The data to convert
off – Offset in array where conversion should begin
len – Length of data to convert
options – Specified options
Throws:
IOException – if there is an error
NullPointerException – if source array is null
IllegalArgumentException – if source array, offset, or length are invalid
See Also:
GZIP
DO_BREAK_LINES
Returns:
The Base64-encoded data as a String
Since:
2.3.1/**
     * Similar to {@link #encodeBytes(byte[], int, int, int)} but returns a byte array instead of instantiating a String. This
     * is more efficient if you're working with I/O streams and have large data sets to encode.
     *
     *
     * @param source The data to convert
     * @param off Offset in array where conversion should begin
     * @param len Length of data to convert
     * @param options Specified options
     * @return The Base64-encoded data as a String
     * @see Base64#GZIP
     * @see Base64#DO_BREAK_LINES
     * @throws java.io.IOException if there is an error
     * @throws NullPointerException if source array is null
     * @throws IllegalArgumentException if source array, offset, or length are invalid
     * @since 2.3.1
     */
    public static byte[] encodeBytesToBytes(byte[] source, int off, int len, int options) throws java.io.IOException {

        if (source == null) {
            throw new NullPointerException("Cannot serialize a null array.");
        } // end if: null

        if (off < 0) {
            throw new IllegalArgumentException("Cannot have negative offset: " + off);
        } // end if: off < 0

        if (len < 0) {
            throw new IllegalArgumentException("Cannot have length offset: " + len);
        } // end if: len < 0

        if (off + len > source.length) {
            throw new IllegalArgumentException(String.format(
                    "Cannot have offset of %d and length of %d with array of length %d", off, len, source.length));
        } // end if: off < 0

        // Compress?
        if ((options & GZIP) != 0) {
            java.io.ByteArrayOutputStream baos = null;
            java.util.zip.GZIPOutputStream gzos = null;
            Base64.OutputStream b64os = null;

            try {
                // GZip -> Base64 -> ByteArray
                baos = new java.io.ByteArrayOutputStream();
                b64os = new Base64.OutputStream(baos, ENCODE | options);
                gzos = new java.util.zip.GZIPOutputStream(b64os);

                gzos.write(source, off, len);
                gzos.close();
            } // end try
            catch (java.io.IOException e) {
                // Catch it and then throw it immediately so that
                // the finally{} block is called for cleanup.
                throw e;
            } // end catch
            finally {
                try {
                    gzos.close();
                } catch (Exception e) {
                }
                try {
                    b64os.close();
                } catch (Exception e) {
                }
                try {
                    baos.close();
                } catch (Exception e) {
                }
            } // end finally

            return baos.toByteArray();
        } // end if: compress

        // Else, don't compress. Better not to use streams at all then.
        else {
            boolean breakLines = (options & DO_BREAK_LINES) != 0;

            // int len43 = len * 4 / 3;
            // byte[] outBuff = new byte[ ( len43 ) // Main 4:3
            // + ( (len % 3) > 0 ? 4 : 0 ) // Account for padding
            // + (breakLines ? ( len43 / MAX_LINE_LENGTH ) : 0) ]; // New lines
            // Try to determine more precisely how big the array needs to be.
            // If we get it right, we don't have to do an array copy, and
            // we save a bunch of memory.
            int encLen = (len / 3) * 4 + (len % 3 > 0 ? 4 : 0); // Bytes needed for actual encoding
            if (breakLines) {
                encLen += encLen / MAX_LINE_LENGTH; // Plus extra newline characters
            }
            byte[] outBuff = new byte[encLen];

            int d = 0;
            int e = 0;
            int len2 = len - 2;
            int lineLength = 0;
            for (; d < len2; d += 3, e += 4) {
                encode3to4(source, d + off, 3, outBuff, e, options);

                lineLength += 4;
                if (breakLines && lineLength >= MAX_LINE_LENGTH) {
                    outBuff[e + 4] = NEW_LINE;
                    e++;
                    lineLength = 0;
                } // end if: end of line
            } // en dfor: each piece of array

            if (d < len) {
                encode3to4(source, d + off, len - d, outBuff, e, options);
                e += 4;
            } // end if: some padding needed

            // Only resize array if we didn't guess it right.
            if (e <= outBuff.length - 1) {
                // If breaking lines and the last byte falls right at
                // the line length (76 bytes per line), there will be
                // one extra byte, and the array will need to be resized.
                // Not too bad of an estimate on array size, I'd say.
                byte[] finalOut = new byte[e];
                System.arraycopy(outBuff, 0, finalOut, 0, e);
                // System.err.println("Having to resize array from " + outBuff.length + " to " + e );
                return finalOut;
            } else {
                // System.err.println("No need to resize array.");
                return outBuff;
            }

        } // end else: don't compress

    } // end encodeBytesToBytes

    /* ******** D E C O D I N G M E T H O D S ******** */

    
Decodes four bytes from array source and writes the resulting bytes (up to three of them) to
destination. The source and destination arrays can be manipulated anywhere along their length by specifying
srcOffset and destOffset. This method does not check to make sure your arrays are large enough to
accommodate srcOffset + 4 for the source array or destOffset + 3 for the
destination array. This method returns the actual number of bytes that were converted from the Base64
encoding.

This is the lowest level of the decoding methods with all possible parameters.

Params:
source – the array to convert
srcOffset – the index where conversion begins
destination – the array to hold the conversion
destOffset – the index where output will be put
options – alphabet type is pulled from this (standard, url-safe, ordered)
Throws:
NullPointerException – if source or destination arrays are null
IllegalArgumentException – if srcOffset or destOffset are invalid or there is not enough room in the array.
Returns:
the number of decoded bytes converted
Since:
1.3/**
     * Decodes four bytes from array <var>source</var> and writes the resulting bytes (up to three of them) to
     * <var>destination</var>. The source and destination arrays can be manipulated anywhere along their length by specifying
     * <var>srcOffset</var> and <var>destOffset</var>. This method does not check to make sure your arrays are large enough to
     * accommodate <var>srcOffset</var> + 4 for the <var>source</var> array or <var>destOffset</var> + 3 for the
     * <var>destination</var> array. This method returns the actual number of bytes that were converted from the Base64
     * encoding.
     * <p>
     * This is the lowest level of the decoding methods with all possible parameters.
     * </p>
     *
     *
     * @param source the array to convert
     * @param srcOffset the index where conversion begins
     * @param destination the array to hold the conversion
     * @param destOffset the index where output will be put
     * @param options alphabet type is pulled from this (standard, url-safe, ordered)
     * @return the number of decoded bytes converted
     * @throws NullPointerException if source or destination arrays are null
     * @throws IllegalArgumentException if srcOffset or destOffset are invalid or there is not enough room in the array.
     * @since 1.3
     */
    private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset, int options) {

        // Lots of error checking and exception throwing
        if (source == null) {
            throw new NullPointerException("Source array was null.");
        } // end if
        if (destination == null) {
            throw new NullPointerException("Destination array was null.");
        } // end if
        if (srcOffset < 0 || srcOffset + 3 >= source.length) {
            throw new IllegalArgumentException(String.format(
                    "Source array with length %d cannot have offset of %d and still process four bytes.", source.length,
                    srcOffset));
        } // end if
        if (destOffset < 0 || destOffset + 2 >= destination.length) {
            throw new IllegalArgumentException(String.format(
                    "Destination array with length %d cannot have offset of %d and still store three bytes.",
                    destination.length, destOffset));
        } // end if

        byte[] DECODABET = getDecodabet(options);

        // Example: Dk==
        if (source[srcOffset + 2] == EQUALS_SIGN) {
            // Two ways to do the same thing. Don't know which way I like best.
            // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
            // | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
            int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12);

            destination[destOffset] = (byte) (outBuff >>> 16);
            return 1;
        }

        // Example: DkL=
        else if (source[srcOffset + 3] == EQUALS_SIGN) {
            // Two ways to do the same thing. Don't know which way I like best.
            // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
            // | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
            // | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
            int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
                    | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6);

            destination[destOffset] = (byte) (outBuff >>> 16);
            destination[destOffset + 1] = (byte) (outBuff >>> 8);
            return 2;
        }

        // Example: DkLE
        else {
            // Two ways to do the same thing. Don't know which way I like best.
            // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
            // | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
            // | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 )
            // | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 );
            int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18) | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
                    | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6) | ((DECODABET[source[srcOffset + 3]] & 0xFF));

            destination[destOffset] = (byte) (outBuff >> 16);
            destination[destOffset + 1] = (byte) (outBuff >> 8);
            destination[destOffset + 2] = (byte) (outBuff);

            return 3;
        }
    } // end decodeToBytes

    
Low-level access to decoding ASCII characters in the form of a byte array. Ignores GUNZIP option, if it's
set. This is not generally a recommended method, although it is used internally as part of the decoding process.
Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and
aren't gzipping), consider this method.
Params:
source – The Base64 encoded data
Returns:
decoded data
Since:
2.3.1/**
     * Low-level access to decoding ASCII characters in the form of a byte array. <strong>Ignores GUNZIP option, if it's
     * set.</strong> This is not generally a recommended method, although it is used internally as part of the decoding process.
     * Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and
     * aren't gzipping), consider this method.
     *
     * @param source The Base64 encoded data
     * @return decoded data
     * @since 2.3.1
     */
    public static byte[] decode(byte[] source) throws java.io.IOException {
        byte[] decoded = null;
        // try {
        decoded = decode(source, 0, source.length, Base64.NO_OPTIONS);
        // } catch( java.io.IOException ex ) {
        // assert false : "IOExceptions only come from GZipping, which is turned off: " + ex.getMessage();
        // }
        return decoded;
    }

    
Low-level access to decoding ASCII characters in the form of a byte array. Ignores GUNZIP option, if it's
set. This is not generally a recommended method, although it is used internally as part of the decoding process.
Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and
aren't gzipping), consider this method.
Params:
source – The Base64 encoded data
off – The offset of where to begin decoding
len – The length of characters to decode
options – Can specify options such as alphabet type to use
Throws:
IOException – If bogus characters exist in source data
Returns:
decoded data
Since:
1.3/**
     * Low-level access to decoding ASCII characters in the form of a byte array. <strong>Ignores GUNZIP option, if it's
     * set.</strong> This is not generally a recommended method, although it is used internally as part of the decoding process.
     * Special case: if len = 0, an empty array is returned. Still, if you need more speed and reduced memory footprint (and
     * aren't gzipping), consider this method.
     *
     * @param source The Base64 encoded data
     * @param off The offset of where to begin decoding
     * @param len The length of characters to decode
     * @param options Can specify options such as alphabet type to use
     * @return decoded data
     * @throws java.io.IOException If bogus characters exist in source data
     * @since 1.3
     */
    public static byte[] decode(byte[] source, int off, int len, int options) throws java.io.IOException {

        // Lots of error checking and exception throwing
        if (source == null) {
            throw new NullPointerException("Cannot decode null source array.");
        } // end if
        if (off < 0 || off + len > source.length) {
            throw new IllegalArgumentException(String.format(
                    "Source array with length %d cannot have offset of %d and process %d bytes.", source.length, off, len));
        } // end if

        if (len == 0) {
            return new byte[0];
        } else if (len < 4) {
            throw new IllegalArgumentException(
                    "Base64-encoded string must have at least four characters, but length specified was " + len);
        } // end if

        byte[] DECODABET = getDecodabet(options);

        int len34 = len * 3 / 4; // Estimate on array size
        byte[] outBuff = new byte[len34]; // Upper limit on size of output
        int outBuffPosn = 0; // Keep track of where we're writing

        byte[] b4 = new byte[4]; // Four byte buffer from source, eliminating white space
        int b4Posn = 0; // Keep track of four byte input buffer
        int i = 0; // Source array counter
        byte sbiDecode = 0; // Special value from DECODABET

        for (i = off; i < off + len; i++) { // Loop through source

            sbiDecode = DECODABET[source[i] & 0xFF];

            // White space, Equals sign, or legit Base64 character
            // Note the values such as -5 and -9 in the
            // DECODABETs at the top of the file.
            if (sbiDecode >= WHITE_SPACE_ENC) {
                if (sbiDecode >= EQUALS_SIGN_ENC) {
                    b4[b4Posn++] = source[i]; // Save non-whitespace
                    if (b4Posn > 3) { // Time to decode?
                        outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn, options);
                        b4Posn = 0;

                        // If that was the equals sign, break out of 'for' loop
                        if (source[i] == EQUALS_SIGN) {
                            break;
                        } // end if: equals sign
                    } // end if: quartet built
                } // end if: equals sign or better
            } // end if: white space, equals sign or better
            else {
                // There's a bad input character in the Base64 stream.
                throw new java.io.IOException(String.format("Bad Base64 input character decimal %d in array position %d",
                        ((int) source[i]) & 0xFF, i));
            } // end else:
        } // each input character

        byte[] out = new byte[outBuffPosn];
        System.arraycopy(outBuff, 0, out, 0, outBuffPosn);
        return out;
    } // end decode

    
Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
Params:
s – the string to decode
Throws:
IOException – If there is a problem
Returns:
the decoded data
Since:
1.4/**
     * Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
     *
     * @param s the string to decode
     * @return the decoded data
     * @throws java.io.IOException If there is a problem
     * @since 1.4
     */
    public static byte[] decode(String s) throws java.io.IOException {
        return decode(s, NO_OPTIONS);
    }

    
Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
Params:
s – the string to decode
options – encode options such as URL_SAFE
Throws:
IOException – if there is an error
NullPointerException – if s is null
Returns:
the decoded data
Since:
1.4/**
     * Decodes data from Base64 notation, automatically detecting gzip-compressed data and decompressing it.
     *
     * @param s the string to decode
     * @param options encode options such as URL_SAFE
     * @return the decoded data
     * @throws java.io.IOException if there is an error
     * @throws NullPointerException if <tt>s</tt> is null
     * @since 1.4
     */
    public static byte[] decode(String s, int options) throws java.io.IOException {

        if (s == null) {
            throw new NullPointerException("Input string was null.");
        } // end if

        byte[] bytes = s.getBytes(StandardCharsets.US_ASCII);

          // </change>

        // Decode
        bytes = decode(bytes, 0, bytes.length, options);

        // Check to see if it's gzip-compressed
        // GZIP Magic Two-Byte Number: 0x8b1f (35615)
        boolean dontGunzip = (options & DONT_GUNZIP) != 0;
        if ((bytes != null) && (bytes.length >= 4) && (!dontGunzip)) {

            int head = ((int) bytes[0] & 0xff) | ((bytes[1] << 8) & 0xff00);
            if (java.util.zip.GZIPInputStream.GZIP_MAGIC == head) {
                java.io.ByteArrayInputStream bais = null;
                java.util.zip.GZIPInputStream gzis = null;
                java.io.ByteArrayOutputStream baos = null;
                byte[] buffer = new byte[2048];
                int length = 0;

                try {
                    baos = new java.io.ByteArrayOutputStream();
                    bais = new java.io.ByteArrayInputStream(bytes);
                    gzis = new java.util.zip.GZIPInputStream(bais);

                    while ((length = gzis.read(buffer)) >= 0) {
                        baos.write(buffer, 0, length);
                    } // end while: reading input

                    // No error? Get new bytes.
                    bytes = baos.toByteArray();

                } // end try
                catch (java.io.IOException e) {
                    UndertowLogger.REQUEST_IO_LOGGER.ioException(e);
                    // Just return originally-decoded bytes
                } // end catch
                finally {
                    try {
                        baos.close();
                    } catch (Exception e) {
                    }
                    try {
                        gzis.close();
                    } catch (Exception e) {
                    }
                    try {
                        bais.close();
                    } catch (Exception e) {
                    }
                } // end finally

            } // end if: gzipped
        } // end if: bytes.length >= 2

        return bytes;
    } // end decode

    
Attempts to decode Base64 data and deserialize a Java Object within. Returns null if there was an error.
Params:
encodedObject – The Base64 data to decode
Throws:
NullPointerException – if encodedObject is null
IOException – if there is a general error
ClassNotFoundException – if the decoded object is of a class that cannot be found by the JVM
Returns:
The decoded and deserialized object
Since:
1.5/**
     * Attempts to decode Base64 data and deserialize a Java Object within. Returns <tt>null</tt> if there was an error.
     *
     * @param encodedObject The Base64 data to decode
     * @return The decoded and deserialized object
     * @throws NullPointerException if encodedObject is null
     * @throws java.io.IOException if there is a general error
     * @throws ClassNotFoundException if the decoded object is of a class that cannot be found by the JVM
     * @since 1.5
     */
    public static Object decodeToObject(String encodedObject) throws java.io.IOException, ClassNotFoundException {
        return decodeToObject(encodedObject, NO_OPTIONS, null);
    }

    
Attempts to decode Base64 data and deserialize a Java Object within. Returns null if there was an error. If
loader is not null, it will be the class loader used when deserializing.
Params:
encodedObject – The Base64 data to decode
options – Various parameters related to decoding
loader – Optional class loader to use in deserializing classes.
Throws:
NullPointerException – if encodedObject is null
IOException – if there is a general error
ClassNotFoundException – if the decoded object is of a class that cannot be found by the JVM
Returns:
The decoded and deserialized object
Since:
2.3.4/**
     * Attempts to decode Base64 data and deserialize a Java Object within. Returns <tt>null</tt> if there was an error. If
     * <tt>loader</tt> is not null, it will be the class loader used when deserializing.
     *
     * @param encodedObject The Base64 data to decode
     * @param options Various parameters related to decoding
     * @param loader Optional class loader to use in deserializing classes.
     * @return The decoded and deserialized object
     * @throws NullPointerException if encodedObject is null
     * @throws java.io.IOException if there is a general error
     * @throws ClassNotFoundException if the decoded object is of a class that cannot be found by the JVM
     * @since 2.3.4
     */
    public static Object decodeToObject(String encodedObject, int options, final ClassLoader loader)
            throws java.io.IOException, ClassNotFoundException {

        // Decode and gunzip if necessary
        byte[] objBytes = decode(encodedObject, options);

        java.io.ByteArrayInputStream bais = null;
        java.io.ObjectInputStream ois = null;
        Object obj = null;

        try {
            bais = new java.io.ByteArrayInputStream(objBytes);

            // If no custom class loader is provided, use Java's builtin OIS.
            if (loader == null) {
                ois = new java.io.ObjectInputStream(bais);
            } // end if: no loader provided

            // Else make a customized object input stream that uses
            // the provided class loader.
            else {
                ois = new java.io.ObjectInputStream(bais) {
                    @Override
                    public Class<?> resolveClass(java.io.ObjectStreamClass streamClass) throws java.io.IOException,
                            ClassNotFoundException {
                        Class c = Class.forName(streamClass.getName(), false, loader);
                        if (c == null) {
                            return super.resolveClass(streamClass);
                        } else {
                            return c; // Class loader knows of this class.
                        } // end else: not null
                    } // end resolveClass
                }; // end ois
            } // end else: no custom class loader

            obj = ois.readObject();
        } // end try
        catch (java.io.IOException e) {
            throw e; // Catch and throw in order to execute finally{}
        } // end catch
        catch (ClassNotFoundException e) {
            throw e; // Catch and throw in order to execute finally{}
        } // end catch
        finally {
            try {
                bais.close();
            } catch (Exception e) {
            }
            try {
                ois.close();
            } catch (Exception e) {
            }
        } // end finally

        return obj;
    } // end decodeObject

    
Convenience method for encoding data to a file.

As of v 2.3, if there is a error, the method will throw an java.io.IOException. This is new to v2.3! In earlier
versions, it just returned false, but in retrospect that's a pretty poor way to handle it.

Params:
dataToEncode – byte array of data to encode in base64 form
filename – Filename for saving encoded data
Throws:
IOException – if there is an error
NullPointerException – if dataToEncode is null
Since:
2.1/**
     * Convenience method for encoding data to a file.
     *
     * <p>
     * As of v 2.3, if there is a error, the method will throw an java.io.IOException. <b>This is new to v2.3!</b> In earlier
     * versions, it just returned false, but in retrospect that's a pretty poor way to handle it.
     * </p>
     *
     * @param dataToEncode byte array of data to encode in base64 form
     * @param filename Filename for saving encoded data
     * @throws java.io.IOException if there is an error
     * @throws NullPointerException if dataToEncode is null
     * @since 2.1
     */
    public static void encodeToFile(byte[] dataToEncode, String filename) throws java.io.IOException {

        if (dataToEncode == null) {
            throw new NullPointerException("Data to encode was null.");
        } // end iff

        Base64.OutputStream bos = null;
        try {
            bos = new Base64.OutputStream(new java.io.FileOutputStream(filename), Base64.ENCODE);
            bos.write(dataToEncode);
        } // end try
        catch (java.io.IOException e) {
            throw e; // Catch and throw to execute finally{} block
        } // end catch: java.io.IOException
        finally {
            try {
                bos.close();
            } catch (Exception e) {
            }
        } // end finally

    } // end encodeToFile

    
Convenience method for decoding data to a file.

As of v 2.3, if there is a error, the method will throw an java.io.IOException. This is new to v2.3! In earlier
versions, it just returned false, but in retrospect that's a pretty poor way to handle it.

Params:
dataToDecode – Base64-encoded data as a string
filename – Filename for saving decoded data
Throws:
IOException – if there is an error
Since:
2.1/**
     * Convenience method for decoding data to a file.
     *
     * <p>
     * As of v 2.3, if there is a error, the method will throw an java.io.IOException. <b>This is new to v2.3!</b> In earlier
     * versions, it just returned false, but in retrospect that's a pretty poor way to handle it.
     * </p>
     *
     * @param dataToDecode Base64-encoded data as a string
     * @param filename Filename for saving decoded data
     * @throws java.io.IOException if there is an error
     * @since 2.1
     */
    public static void decodeToFile(String dataToDecode, String filename) throws java.io.IOException {

        Base64.OutputStream bos = null;
        try {
            bos = new Base64.OutputStream(new java.io.FileOutputStream(filename), Base64.DECODE);
            bos.write(dataToDecode.getBytes(StandardCharsets.US_ASCII));
        } // end try
        catch (java.io.IOException e) {
            throw e; // Catch and throw to execute finally{} block
        } // end catch: java.io.IOException
        finally {
            try {
                bos.close();
            } catch (Exception e) {
            }
        } // end finally

    } // end decodeToFile

    
Convenience method for reading a base64-encoded file and decoding it.

As of v 2.3, if there is a error, the method will throw an java.io.IOException. This is new to v2.3! In earlier
versions, it just returned false, but in retrospect that's a pretty poor way to handle it.

Params:
filename – Filename for reading encoded data
Throws:
IOException – if there is an error
Returns:
decoded byte array
Since:
2.1/**
     * Convenience method for reading a base64-encoded file and decoding it.
     *
     * <p>
     * As of v 2.3, if there is a error, the method will throw an java.io.IOException. <b>This is new to v2.3!</b> In earlier
     * versions, it just returned false, but in retrospect that's a pretty poor way to handle it.
     * </p>
     *
     * @param filename Filename for reading encoded data
     * @return decoded byte array
     * @throws java.io.IOException if there is an error
     * @since 2.1
     */
    public static byte[] decodeFromFile(String filename) throws java.io.IOException {

        byte[] decodedData = null;
        Base64.InputStream bis = null;
        try {
            // Set up some useful variables
            Path file = Paths.get(filename);
            byte[] buffer;
            int length = 0;
            int numBytes;

            // Check for size of file
            if (Files.size(file) > Integer.MAX_VALUE) {
                throw new java.io.IOException("File is too big for this convenience method (" + Files.size(file) + " bytes).");
            } // end if: file too big for int index
            buffer = new byte[(int) Files.size(file)];

            // Open a stream
            bis = new Base64.InputStream(new java.io.BufferedInputStream(Files.newInputStream(file)), Base64.DECODE);

            // Read until done
            while ((numBytes = bis.read(buffer, length, 4096)) >= 0) {
                length += numBytes;
            } // end while

            // Save in a variable to return
            decodedData = new byte[length];
            System.arraycopy(buffer, 0, decodedData, 0, length);

        } // end try
        catch (java.io.IOException e) {
            throw e; // Catch and release to execute finally{}
        } // end catch: java.io.IOException
        finally {
            try {
                bis.close();
            } catch (Exception e) {
            }
        } // end finally

        return decodedData;
    } // end decodeFromFile

    
Convenience method for reading a binary file and base64-encoding it.

As of v 2.3, if there is a error, the method will throw an java.io.IOException. This is new to v2.3! In earlier
versions, it just returned false, but in retrospect that's a pretty poor way to handle it.

Params:
filename – Filename for reading binary data
Throws:
IOException – if there is an error
Returns:
base64-encoded string
Since:
2.1/**
     * Convenience method for reading a binary file and base64-encoding it.
     *
     * <p>
     * As of v 2.3, if there is a error, the method will throw an java.io.IOException. <b>This is new to v2.3!</b> In earlier
     * versions, it just returned false, but in retrospect that's a pretty poor way to handle it.
     * </p>
     *
     * @param filename Filename for reading binary data
     * @return base64-encoded string
     * @throws java.io.IOException if there is an error
     * @since 2.1
     */
    public static String encodeFromFile(String filename) throws java.io.IOException {

        String encodedData = null;
        Base64.InputStream bis = null;
        try {
            // Set up some useful variables
            Path file = Paths.get(filename);
            byte[] buffer = new byte[Math.max((int) (Files.size(file) * 1.4 + 1), 40)]; // Need max() for math on small files
                                                                                     // (v2.2.1); Need +1 for a few corner cases
                                                                                     // (v2.3.5)
            int length = 0;
            int numBytes;

            // Open a stream
            bis = new Base64.InputStream(new java.io.BufferedInputStream(Files.newInputStream(file)), Base64.ENCODE);

            // Read until done
            while ((numBytes = bis.read(buffer, length, 4096)) >= 0) {
                length += numBytes;
            } // end while

            // Save in a variable to return
            encodedData = new String(buffer, 0, length, StandardCharsets.US_ASCII);

        } // end try
        catch (java.io.IOException e) {
            throw e; // Catch and release to execute finally{}
        } // end catch: java.io.IOException
        finally {
            try {
                bis.close();
            } catch (Exception e) {
            }
        } // end finally

        return encodedData;
    } // end encodeFromFile

    
Reads infile and encodes it to outfile.
Params:
infile – Input file
outfile – Output file
Throws:
IOException – if there is an error
Since:
2.2/**
     * Reads <tt>infile</tt> and encodes it to <tt>outfile</tt>.
     *
     * @param infile Input file
     * @param outfile Output file
     * @throws java.io.IOException if there is an error
     * @since 2.2
     */
    public static void encodeFileToFile(String infile, String outfile) throws java.io.IOException {

        String encoded = Base64.encodeFromFile(infile);
        java.io.OutputStream out = null;
        try {
            out = new java.io.BufferedOutputStream(new java.io.FileOutputStream(outfile));
            out.write(encoded.getBytes(StandardCharsets.US_ASCII)); // Strict, 7-bit output.
        } // end try
        catch (java.io.IOException e) {
            throw e; // Catch and release to execute finally{}
        } // end catch
        finally {
            try {
                out.close();
            } catch (Exception ex) {
            }
        } // end finally
    } // end encodeFileToFile

    
Reads infile and decodes it to outfile.
Params:
infile – Input file
outfile – Output file
Throws:
IOException – if there is an error
Since:
2.2/**
     * Reads <tt>infile</tt> and decodes it to <tt>outfile</tt>.
     *
     * @param infile Input file
     * @param outfile Output file
     * @throws java.io.IOException if there is an error
     * @since 2.2
     */
    public static void decodeFileToFile(String infile, String outfile) throws java.io.IOException {

        byte[] decoded = Base64.decodeFromFile(infile);
        java.io.OutputStream out = null;
        try {
            out = new java.io.BufferedOutputStream(new java.io.FileOutputStream(outfile));
            out.write(decoded);
        } // end try
        catch (java.io.IOException e) {
            throw e; // Catch and release to execute finally{}
        } // end catch
        finally {
            try {
                out.close();
            } catch (Exception ex) {
            }
        } // end finally
    } // end decodeFileToFile

    /* ******** I N N E R C L A S S I N P U T S T R E A M ******** */

    
A InputStream will read data from another java.io.InputStream, given in the constructor, and
encode/decode to/from Base64 notation on the fly.
See Also:
Base64
Since:
1.3/**
     * A {@link Base64.InputStream} will read data from another <tt>java.io.InputStream</tt>, given in the constructor, and
     * encode/decode to/from Base64 notation on the fly.
     *
     * @see Base64
     * @since 1.3
     */
    public static class InputStream extends java.io.FilterInputStream {

        private boolean encode; // Encoding or decoding
        private int position; // Current position in the buffer
        private byte[] buffer; // Small buffer holding converted data
        private int bufferLength; // Length of buffer (3 or 4)
        private int numSigBytes; // Number of meaningful bytes in the buffer
        private int lineLength;
        private boolean breakLines; // Break lines at less than 80 characters
        private int options; // Record options used to create the stream.
        private byte[] decodabet; // Local copies to avoid extra method calls

        
Constructs a InputStream in DECODE mode. 
Params:
in – the java.io.InputStream from which to read data.
Since:
1.3/**
         * Constructs a {@link Base64.InputStream} in DECODE mode.
         *
         * @param in the <tt>java.io.InputStream</tt> from which to read data.
         * @since 1.3
         */
        InputStream(java.io.InputStream in) {
            this(in, DECODE);
        } // end constructor

        
Constructs a InputStream in either ENCODE or DECODE mode. 

Valid options:
  ENCODE or DECODE: Encode or Decode as data is read.
  DO_BREAK_LINES: break lines at 76 characters
    (only meaningful when encoding)


Example: new Base64.InputStream( in, Base64.DECODE )
Params:
in – the java.io.InputStream from which to read data.
options – Specified options
See Also:
Base64.ENCODE
Base64.DECODE
Base64.DO_BREAK_LINES
Since:
2.0/**
         * Constructs a {@link Base64.InputStream} in either ENCODE or DECODE mode.
         * <p>
         * Valid options:
         *
         * <pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DO_BREAK_LINES: break lines at 76 characters
         *     (only meaningful when encoding)</i>
         * </pre>
         * <p>
         * Example: <code>new Base64.InputStream( in, Base64.DECODE )</code>
         *
         *
         * @param in the <tt>java.io.InputStream</tt> from which to read data.
         * @param options Specified options
         * @see Base64#ENCODE
         * @see Base64#DECODE
         * @see Base64#DO_BREAK_LINES
         * @since 2.0
         */
        InputStream(java.io.InputStream in, int options) {

            super(in);
            this.options = options; // Record for later
            this.breakLines = (options & DO_BREAK_LINES) > 0;
            this.encode = (options & ENCODE) > 0;
            this.bufferLength = encode ? 4 : 3;
            this.buffer = new byte[bufferLength];
            this.position = -1;
            this.lineLength = 0;
            this.decodabet = getDecodabet(options);
        } // end constructor

        
Reads enough of the input stream to convert to/from Base64 and returns the next byte.
Returns:
next byte
Since:
1.3/**
         * Reads enough of the input stream to convert to/from Base64 and returns the next byte.
         *
         * @return next byte
         * @since 1.3
         */
        @Override
        public int read() throws java.io.IOException {

            // Do we need to get data?
            if (position < 0) {
                if (encode) {
                    byte[] b3 = new byte[3];
                    int numBinaryBytes = 0;
                    for (int i = 0; i < 3; i++) {
                        int b = in.read();

                        // If end of stream, b is -1.
                        if (b >= 0) {
                            b3[i] = (byte) b;
                            numBinaryBytes++;
                        } else {
                            break; // out of for loop
                        } // end else: end of stream

                    } // end for: each needed input byte

                    if (numBinaryBytes > 0) {
                        encode3to4(b3, 0, numBinaryBytes, buffer, 0, options);
                        position = 0;
                        numSigBytes = 4;
                    } // end if: got data
                    else {
                        return -1; // Must be end of stream
                    } // end else
                } // end if: encoding

                // Else decoding
                else {
                    byte[] b4 = new byte[4];
                    int i = 0;
                    for (i = 0; i < 4; i++) {
                        // Read four "meaningful" bytes:
                        int b = 0;
                        do {
                            b = in.read();
                        } while (b >= 0 && decodabet[b & 0x7f] <= WHITE_SPACE_ENC);

                        if (b < 0) {
                            break; // Reads a -1 if end of stream
                        } // end if: end of stream

                        b4[i] = (byte) b;
                    } // end for: each needed input byte

                    if (i == 4) {
                        numSigBytes = decode4to3(b4, 0, buffer, 0, options);
                        position = 0;
                    } // end if: got four characters
                    else if (i == 0) {
                        return -1;
                    } // end else if: also padded correctly
                    else {
                        // Must have broken out from above.
                        throw new java.io.IOException("Improperly padded Base64 input.");
                    } // end

                } // end else: decode
            } // end else: get data

            // Got data?
            if (position >= 0) {
                // End of relevant data?
                if ( /* !encode && */position >= numSigBytes) {
                    return -1;
                } // end if: got data

                if (encode && breakLines && lineLength >= MAX_LINE_LENGTH) {
                    lineLength = 0;
                    return '\n';
                } // end if
                else {
                    lineLength++; // This isn't important when decoding
                                  // but throwing an extra "if" seems
                                  // just as wasteful.

                    int b = buffer[position++];

                    if (position >= bufferLength) {
                        position = -1;
                    } // end if: end

                    return b & 0xFF; // This is how you "cast" a byte that's
                                     // intended to be unsigned.
                } // end else
            } // end if: position >= 0

            // Else error
            else {
                throw new java.io.IOException("Error in Base64 code reading stream.");
            } // end else
        } // end read

        
Calls read() repeatedly until the end of stream is reached or len bytes are read. Returns number
of bytes read into array or -1 if end of stream is encountered.
Params:
dest – array to hold values
off – offset for array
len – max number of bytes to read into array
Returns:
bytes read into array or -1 if end of stream is encountered.
Since:
1.3/**
         * Calls {@link #read()} repeatedly until the end of stream is reached or <var>len</var> bytes are read. Returns number
         * of bytes read into array or -1 if end of stream is encountered.
         *
         * @param dest array to hold values
         * @param off offset for array
         * @param len max number of bytes to read into array
         * @return bytes read into array or -1 if end of stream is encountered.
         * @since 1.3
         */
        @Override
        public int read(byte[] dest, int off, int len) throws java.io.IOException {
            int i;
            int b;
            for (i = 0; i < len; i++) {
                b = read();

                if (b >= 0) {
                    dest[off + i] = (byte) b;
                } else if (i == 0) {
                    return -1;
                } else {
                    break; // Out of 'for' loop
                } // Out of 'for' loop
            } // end for: each byte read
            return i;
        } // end read

    } // end inner class InputStream

    /* ******** I N N E R C L A S S O U T P U T S T R E A M ******** */

    
A OutputStream will write data to another java.io.OutputStream, given in the constructor, and
encode/decode to/from Base64 notation on the fly.
See Also:
Base64
Since:
1.3/**
     * A {@link Base64.OutputStream} will write data to another <tt>java.io.OutputStream</tt>, given in the constructor, and
     * encode/decode to/from Base64 notation on the fly.
     *
     * @see Base64
     * @since 1.3
     */
    public static class OutputStream extends java.io.FilterOutputStream {

        private boolean encode;
        private int position;
        private byte[] buffer;
        private int bufferLength;
        private int lineLength;
        private boolean breakLines;
        private byte[] b4; // Scratch used in a few places
        private boolean suspendEncoding;
        private int options; // Record for later
        private byte[] decodabet; // Local copies to avoid extra method calls

        
Constructs a OutputStream in ENCODE mode. 
Params:
out – the java.io.OutputStream to which data will be written.
Since:
1.3/**
         * Constructs a {@link Base64.OutputStream} in ENCODE mode.
         *
         * @param out the <tt>java.io.OutputStream</tt> to which data will be written.
         * @since 1.3
         */
        OutputStream(java.io.OutputStream out) {
            this(out, ENCODE);
        } // end constructor

        
Constructs a OutputStream in either ENCODE or DECODE mode. 

Valid options:
  ENCODE or DECODE: Encode or Decode as data is read.
  DO_BREAK_LINES: don't break lines at 76 characters
    (only meaningful when encoding)


Example: new Base64.OutputStream( out, Base64.ENCODE )
Params:
out – the java.io.OutputStream to which data will be written.
options – Specified options.
See Also:
Base64.ENCODE
Base64.DECODE
Base64.DO_BREAK_LINES
Since:
1.3/**
         * Constructs a {@link Base64.OutputStream} in either ENCODE or DECODE mode.
         * <p>
         * Valid options:
         *
         * <pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DO_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)</i>
         * </pre>
         * <p>
         * Example: <code>new Base64.OutputStream( out, Base64.ENCODE )</code>
         *
         * @param out the <tt>java.io.OutputStream</tt> to which data will be written.
         * @param options Specified options.
         * @see Base64#ENCODE
         * @see Base64#DECODE
         * @see Base64#DO_BREAK_LINES
         * @since 1.3
         */
        OutputStream(java.io.OutputStream out, int options) {
            super(out);
            this.breakLines = (options & DO_BREAK_LINES) != 0;
            this.encode = (options & ENCODE) != 0;
            this.bufferLength = encode ? 3 : 4;
            this.buffer = new byte[bufferLength];
            this.position = 0;
            this.lineLength = 0;
            this.suspendEncoding = false;
            this.b4 = new byte[4];
            this.options = options;
            this.decodabet = getDecodabet(options);
        } // end constructor

        
Writes the byte to the output stream after converting to/from Base64 notation. When encoding, bytes are buffered
three at a time before the output stream actually gets a write() call. When decoding, bytes are buffered four at a
time.
Params:
theByte – the byte to write
Since:
1.3/**
         * Writes the byte to the output stream after converting to/from Base64 notation. When encoding, bytes are buffered
         * three at a time before the output stream actually gets a write() call. When decoding, bytes are buffered four at a
         * time.
         *
         * @param theByte the byte to write
         * @since 1.3
         */
        @Override
        public void write(int theByte) throws java.io.IOException {
            // Encoding suspended?
            if (suspendEncoding) {
                this.out.write(theByte);
                return;
            } // end if: suspended

            // Encode?
            if (encode) {
                buffer[position++] = (byte) theByte;
                if (position >= bufferLength) { // Enough to encode.

                    this.out.write(encode3to4(b4, buffer, bufferLength, options));

                    lineLength += 4;
                    if (breakLines && lineLength >= MAX_LINE_LENGTH) {
                        this.out.write(NEW_LINE);
                        lineLength = 0;
                    } // end if: end of line

                    position = 0;
                } // end if: enough to output
            } // end if: encoding

            // Else, Decoding
            else {
                // Meaningful Base64 character?
                if (decodabet[theByte & 0x7f] > WHITE_SPACE_ENC) {
                    buffer[position++] = (byte) theByte;
                    if (position >= bufferLength) { // Enough to output.

                        int len = Base64.decode4to3(buffer, 0, b4, 0, options);
                        out.write(b4, 0, len);
                        position = 0;
                    } // end if: enough to output
                } // end if: meaningful base64 character
                else if (decodabet[theByte & 0x7f] != WHITE_SPACE_ENC) {
                    throw new java.io.IOException("Invalid character in Base64 data.");
                } // end else: not white space either
            } // end else: decoding
        } // end write

        
Calls write(int) repeatedly until len bytes are written.
Params:
theBytes – array from which to read bytes
off – offset for array
len – max number of bytes to read into array
Since:
1.3/**
         * Calls {@link #write(int)} repeatedly until <var>len</var> bytes are written.
         *
         * @param theBytes array from which to read bytes
         * @param off offset for array
         * @param len max number of bytes to read into array
         * @since 1.3
         */
        @Override
        public void write(byte[] theBytes, int off, int len) throws java.io.IOException {
            // Encoding suspended?
            if (suspendEncoding) {
                this.out.write(theBytes, off, len);
                return;
            } // end if: suspended

            for (int i = 0; i < len; i++) {
                write(theBytes[off + i]);
            } // end for: each byte written

        } // end write

        
Method added by PHIL. [Thanks, PHIL. -Rob] This pads the buffer without closing the stream.
Throws:
IOException – if there's an error./**
         * Method added by PHIL. [Thanks, PHIL. -Rob] This pads the buffer without closing the stream.
         *
         * @throws java.io.IOException if there's an error.
         */
        public void flushBase64() throws java.io.IOException {
            if (position > 0) {
                if (encode) {
                    out.write(encode3to4(b4, buffer, position, options));
                    position = 0;
                } // end if: encoding
                else {
                    throw new java.io.IOException("Base64 input not properly padded.");
                } // end else: decoding
            } // end if: buffer partially full

        } // end flush

        
Flushes and closes (I think, in the superclass) the stream.
Since:
1.3/**
         * Flushes and closes (I think, in the superclass) the stream.
         *
         * @since 1.3
         */
        @Override
        public void close() throws java.io.IOException {
            // 1. Ensure that pending characters are written
            flushBase64();

            // 2. Actually close the stream
            // Base class both flushes and closes.
            super.close();

            buffer = null;
            out = null;
        } // end close

        
Suspends encoding of the stream. May be helpful if you need to embed a piece of base64-encoded data in a stream.
Throws:
IOException – if there's an error flushing
Since:
1.5.1/**
         * Suspends encoding of the stream. May be helpful if you need to embed a piece of base64-encoded data in a stream.
         *
         * @throws java.io.IOException if there's an error flushing
         * @since 1.5.1
         */
        public void suspendEncoding() throws java.io.IOException {
            flushBase64();
            this.suspendEncoding = true;
        } // end suspendEncoding

        
Resumes encoding of the stream. May be helpful if you need to embed a piece of base64-encoded data in a stream.
Since:
1.5.1/**
         * Resumes encoding of the stream. May be helpful if you need to embed a piece of base64-encoded data in a stream.
         *
         * @since 1.5.1
         */
        public void resumeEncoding() {
            this.suspendEncoding = false;
        } // end resumeEncoding

    } // end inner class OutputStream

} // end class Base64