Base64.java
/*
* 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 (~< 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