content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you 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 org.apache.calcite.avatica.util;
  
  //CHECKSTYLE: OFF
  
  import java.nio.charset.StandardCharsets;
  import java.util.Locale;
  
  /**
   * <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 <code>options</code> 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(java.lang.String, int, java.lang.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 possiblity 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 (<code>int</code>s that you "OR" together).</li>
   *  <li>v1.5.1 - Fixed bug when decompressing and decoding to a
   *   byte[] using <code>decode( String s, boolean gzipCompressed )</code>.
   *   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 pases 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
   */
  public class Base64
  {
  
  /* ********  P U B L I C   F I E L D S  ******** */
  
  
    /** No options specified. Value is zero. */
    public final static int NO_OPTIONS = 0;
  
    /** Specify encoding in first bit. Value is one. */
    public final static int ENCODE = 1;
  
  
    /** Specify decoding in first bit. Value is zero. */
    public final static int DECODE = 0;
  
  
    /** Specify that data should be gzip-compressed in second bit. Value is two. */
    public final static int GZIP = 2;
  
    /** Specify that gzipped data should <em>not</em> be automatically gunzipped. */
    public final static int DONT_GUNZIP = 4;
  
  
    /** Do break lines when encoding. Value is 8. */
    public final static int DO_BREAK_LINES = 8;
  
    /**
     * 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 final static int URL_SAFE = 16;
  
  
    /**
     * 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 final static int ORDERED = 32;
  
  
  /* ********  P R I V A T E   F I E L D S  ******** */
  
  
    /** Maximum line length (76) of Base64 output. */
    private final static int MAX_LINE_LENGTH = 76;
  
  
    /** The equals sign (=) as a byte. */
    private final static byte EQUALS_SIGN = (byte)'=';
  
  
    /** The new line character (\n) as a byte. */
    private final static byte NEW_LINE = (byte)'\n';
  
  
    /** Preferred encoding. */
    private final static String PREFERRED_ENCODING = "US-ASCII";
  
  
    private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in encoding
    private final static 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. */
      /* Host platform me be something funny like EBCDIC, so we hardcode these values. */
    private final static 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.
     **/
    private final static 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:
     * <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 final static 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.
     */
    private final static 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:
     * <a href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
     */
    private final static 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.
     */
    private final static 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 <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 final 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.
     */
    private final 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. */
    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 <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
  
  
    /**
     * <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 <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 <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.
     *
     * <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.
     *
     * <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.
      try {
        return new String( baos.toByteArray(), PREFERRED_ENCODING );
      }   // end try
      catch (java.io.UnsupportedEncodingException uue){
        // Fall back to some Java default
        return new String( baos.toByteArray(), StandardCharsets.UTF_8 );
      }   // end catch
  
    }   // end encode
  
  
  
    /**
     * 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.
     * <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.
     *
     * <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.
     * <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.
      try {
        return new String( encoded, PREFERRED_ENCODING );
      }   // end try
      catch (java.io.UnsupportedEncodingException uue) {
        return new String( encoded, StandardCharsets.UTF_8 );
      }   // end catch
  
    }   // end encodeBytes
  
  
  
  
    /**
     * 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 {@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( Locale.ROOT,
                "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 <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 accomodate <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( Locale.ROOT,
            "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( Locale.ROOT,
            "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. <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. <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( Locale.ROOT,
            "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( Locale.ROOT,
              "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.
     *
     * @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.
     *
     * @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 <code>s</code> 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;
      try {
        bytes = s.getBytes( PREFERRED_ENCODING );
      }   // end try
      catch( java.io.UnsupportedEncodingException uee ) {
        bytes = s.getBytes( StandardCharsets.UTF_8 );
      }   // end catch
      //</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 ) {
            e.printStackTrace();
            // 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 <code>null</code> 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, java.lang.ClassNotFoundException {
      return decodeToObject(encodedObject,NO_OPTIONS,null);
    }
  
  
    /**
     * Attempts to decode Base64 data and deserialize a Java
     * Object within. Returns <code>null</code> if there was an error.
     * If <code>loader</code> 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, java.lang.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( java.lang.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.
     *
     * <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.
     *
     * <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( PREFERRED_ENCODING ) );
      }   // 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.
     *
     * <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
        java.io.File file = new java.io.File( filename );
        byte[] buffer = null;
        int length   = 0;
        int numBytes = 0;
  
        // Check for size of file
        if( file.length() > Integer.MAX_VALUE )
        {
          throw new java.io.IOException( "File is too big for this convenience method (" +
              file.length() + " bytes)." );
        }   // end if: file too big for int index
        buffer = new byte[ (int)file.length() ];
  
        // Open a stream
        bis = new Base64.InputStream(
            new java.io.BufferedInputStream(
                new java.io.FileInputStream( 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.
     *
     * <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
        java.io.File file = new java.io.File( filename );
        byte[] buffer = new byte[ Math.max((int)(file.length() * 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 = 0;
  
        // Open a stream
        bis = new Base64.InputStream(
            new java.io.BufferedInputStream(
                new java.io.FileInputStream( 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, Base64.PREFERRED_ENCODING );
  
      }   // 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 <code>infile</code> and encodes it to <code>outfile</code>.
     *
     * @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("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 <code>infile</code> and decodes it to <code>outfile</code>.
     *
     * @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 {@link Base64.InputStream} will read data from another
     * <code>java.io.InputStream</code>, 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 {@link Base64.InputStream} in DECODE mode.
       *
       * @param in the <code>java.io.InputStream</code> from which to read data.
       * @since 1.3
       */
      public InputStream( java.io.InputStream in ) {
        this( in, DECODE );
      }   // end constructor
  
  
      /**
       * 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)
       * </pre>
       * <p>
       * Example: <code>new Base64.InputStream( in, Base64.DECODE )</code>
       *
       *
       * @param in the <code>java.io.InputStream</code> from which to read data.
       * @param options Specified options
       * @see Base64#ENCODE
       * @see Base64#DECODE
       * @see Base64#DO_BREAK_LINES
       * @since 2.0
       */
      public 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.
       *
       * @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 {@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 {@link Base64.OutputStream} will write data to another
     * <code>java.io.OutputStream</code>, 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 {@link Base64.OutputStream} in ENCODE mode.
       *
       * @param out the <code>java.io.OutputStream</code> to which data will be written.
       * @since 1.3
       */
      public OutputStream( java.io.OutputStream out ) {
        this( out, ENCODE );
      }   // end constructor
  
  
      /**
       * 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)
       * </pre>
       * <p>
       * Example: <code>new Base64.OutputStream( out, Base64.ENCODE )</code>
       *
       * @param out the <code>java.io.OutputStream</code> to which data will be written.
       * @param options Specified options.
       * @see Base64#ENCODE
       * @see Base64#DECODE
       * @see Base64#DO_BREAK_LINES
       * @since 1.3
       */
      public 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.
       *
       * @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: supsended
  
        // 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 {@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: supsended
  
        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 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
       */
      @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 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
       */
      public void resumeEncoding() {
        this.suspendEncoding = false;
      }   // end resumeEncoding
  
  
  
    }   // end inner class OutputStream
  
  
  }   // end class Base64
  
  //CHECKSTYLE: ON
  
  // End Base64.java
  