Base64 encoder/decoder - Java source code

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Olivier Ligny - - 12/03/2008 - vue 11572 fois

Base64 encoder/decoder - Java source code

Encodes and decodes to and from Base64 notation.
Written by Robert Harder

Main methods :

    /**
     * Encodes a byte array into Base64 notation.
     * Does not GZip-compress data.
     *
     * @param source The data to convert
     * @since 1.4
     */
    public static String encodeBytes( byte[] source )

    /**
     * Decodes data from Base64 notation, automatically
     * detecting gzip-compressed data and decompressing it.
     *
     * @param s the string to decode
     * @return the decoded data
     * @since 1.4
     */
    public static byte[] decode( String s )

The Base64.java source code :

/**
* Encodes and decodes to and from Base64 notation.
*
* 
* Change Log:
* 
* <ul>
* <li>v2.1 - Cleaned up javadoc comments and unused variables and methods. Added
* some convenience methods for reading and writing to and from files.</li>
* <li>v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems
* with other encodings (like EBCDIC).</li>
* <li>v2.0.1 - Fixed an error when decoding a single byte, that is, when the
* encoded data was a single byte.</li>
* <li>v2.0 - I got rid of methods that used booleans to set options.
* Now everything is more consolidated and cleaner. The code now detects
* when data that's being decoded is gzip-compressed and will decompress it
* automatically. Generally things are cleaner. You'll probably have to
* change some method calls that you were making to support the new
* options format (<tt>int</tt>s that you "OR" together).</li>
* <li>v1.5.1 - Fixed bug when decompressing and decoding to a
* byte[] using <tt>decode( String s, boolean gzipCompressed )</tt>.
* Added the ability to "suspend" encoding in the Output Stream so
* you can turn on and off the encoding if you need to embed base64
* data in an otherwise "normal" stream (like an XML file).</li>
* <li>v1.5 - Output stream 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>
*
* 
* 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.
* 
*
* @author Robert Harder
* @author rob@iharder.net
* @version 2.1
*/
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. */
 public final static int ENCODE = 1;


 /** Specify decoding. */
 public final static int DECODE = 0;


 /** Specify that data should be gzip-compressed. */
 public final static int GZIP = 2;


 /** Don't break lines when encoding (violates strict Base64 specification) */
 public final static int DONT_BREAK_LINES = 8;


/* ******** 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 = "UTF-8";


 /** The 64 valid Base64 values. */
 private final static byte[] ALPHABET;
 private final static byte[] _NATIVE_ALPHABET = /* May be something funny like EBCDIC */
 {
 (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)'/'
 };

 /** Determine which ALPHABET to use. */
 static
 {
 byte[] __bytes;
 try
 {
 __bytes = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".getBytes( PREFERRED_ENCODING );
 } // end try
 catch (java.io.UnsupportedEncodingException use)
 {
 __bytes = _NATIVE_ALPHABET; // Fall back to native encoding
 } // end catch
 ALPHABET = __bytes;
 } // end static


 /**
 * Translates a Base64 value to either its 6-bit reconstruction value
 * or a negative number indicating some other meaning.
 **/
 private final static byte[] 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 // Decimal 123 - 126
 /*,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 127 - 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 */
 };

 // I think I end up not using the BAD_ENCODING indicator.
 //private final static byte BAD_ENCODING = -9; // Indicates error in encoding
 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


 /** 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 )
 {
 encode3to4( threeBytes, 0, numSigBytes, b4, 0 );
 return b4;
 } // end encode3to4


 /**
 * 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>.
 *
 * @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 )
 {
 // 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



 /**
 * Serializes an object and returns the Base64-encoded
 * version of that serialized object. If the object
 * cannot be serialized or there is another error,
 * the method will return <tt>null</tt>.
 * The object is not GZip-compressed before being encoded.
 *
 * @param serializableObject The object to encode
 * @return The Base64-encoded object
 * @since 1.4
 */
 public static String encodeObject( java.io.Serializable serializableObject )
 {
 return encodeObject( serializableObject, NO_OPTIONS );
 } // end encodeObject


 /**
 * Serializes an object and returns the Base64-encoded
 * version of that serialized object. If the object
 * cannot be serialized or there is another error,
 * the method will return <tt>null</tt>.
 * 
 * Valid options:<pre>
 * GZIP: gzip-compresses object before encoding it.
 * DONT_BREAK_LINES: don't break lines at 76 characters
 * Note: Technically, this makes your encoding non-compliant.
 * </pre>
 * 
 * Example: <code>encodeObject( myObj, Base64.GZIP )</code> or
 * 
 * Example: <code>encodeObject( myObj, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
 *
 * @param serializableObject The object to encode
 * @param options Specified options
 * @return The Base64-encoded object
 * @see Base64#GZIP
 * @see Base64#DONT_BREAK_LINES
 * @since 2.0
 */
 public static String encodeObject( java.io.Serializable serializableObject, int options )
 {
 // Streams
 java.io.ByteArrayOutputStream baos = null;
 java.io.OutputStream b64os = null;
 java.io.ObjectOutputStream oos = null;
 java.util.zip.GZIPOutputStream gzos = null;

 // Isolate options
 int gzip = (options & GZIP);
 int dontBreakLines = (options & DONT_BREAK_LINES);

 try
 {
 // ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
 baos = new java.io.ByteArrayOutputStream();
 b64os = new Base64.OutputStream( baos, ENCODE | dontBreakLines );

 // GZip?
 if( gzip == GZIP )
 {
 gzos = new java.util.zip.GZIPOutputStream( b64os );
 oos = new java.io.ObjectOutputStream( gzos );
 } // end if: gzip
 else
 oos = new java.io.ObjectOutputStream( b64os );

 oos.writeObject( serializableObject );
 } // end try
 catch( java.io.IOException e )
 {
 e.printStackTrace();
 return null;
 } // 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)
 {
 return new String( baos.toByteArray() );
 } // end catch

 } // end encode



 /**
 * Encodes a byte array into Base64 notation.
 * Does not GZip-compress data.
 *
 * @param source The data to convert
 * @since 1.4
 */
 public static String encodeBytes( byte[] source )
 {
 return encodeBytes( source, 0, source.length, NO_OPTIONS );
 } // end encodeBytes


 /**
 * Encodes a byte array into Base64 notation.
 * 
 * Valid options:<pre>
 * GZIP: gzip-compresses object before encoding it.
 * DONT_BREAK_LINES: don't break lines at 76 characters
 * Note: Technically, this makes your encoding non-compliant.
 * </pre>
 * 
 * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
 * 
 * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
 *
 *
 * @param source The data to convert
 * @param options Specified options
 * @see Base64#GZIP
 * @see Base64#DONT_BREAK_LINES
 * @since 2.0
 */
 public static String encodeBytes( byte[] source, int options )
 {
 return encodeBytes( source, 0, source.length, options );
 } // end encodeBytes


 /**
 * Encodes a byte array into Base64 notation.
 * Does not GZip-compress data.
 *
 * @param source The data to convert
 * @param off Offset in array where conversion should begin
 * @param len Length of data to convert
 * @since 1.4
 */
 public static String encodeBytes( byte[] source, int off, int len )
 {
 return encodeBytes( source, off, len, NO_OPTIONS );
 } // end encodeBytes



 /**
 * Encodes a byte array into Base64 notation.
 * 
 * Valid options:<pre>
 * GZIP: gzip-compresses object before encoding it.
 * DONT_BREAK_LINES: don't break lines at 76 characters
 * Note: Technically, this makes your encoding non-compliant.
 * </pre>
 * 
 * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
 * 
 * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
 *
 *
 * @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
 * @see Base64#GZIP
 * @see Base64#DONT_BREAK_LINES
 * @since 2.0
 */
 public static String encodeBytes( byte[] source, int off, int len, int options )
 {
 // Isolate options
 int dontBreakLines = ( options & DONT_BREAK_LINES );
 int gzip = ( options & GZIP );

 // Compress?
 if( gzip == GZIP )
 {
 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 | dontBreakLines );
 gzos = new java.util.zip.GZIPOutputStream( b64os );

 gzos.write( source, off, len );
 gzos.close();
 } // end try
 catch( java.io.IOException e )
 {
 e.printStackTrace();
 return null;
 } // end catch
 finally
 {
 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)
 {
 return new String( baos.toByteArray() );
 } // end catch
 } // end if: compress

 // Else, don't compress. Better not to use streams at all then.
 else
 {
 // Convert option to boolean in way that code likes it.
 boolean breakLines = dontBreakLines == 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
 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 );

 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 );
 e += 4;
 } // end if: some padding needed


 // Return value according to relevant encoding.
 try
 {
 return new String( outBuff, 0, e, PREFERRED_ENCODING );
 } // end try
 catch (java.io.UnsupportedEncodingException uue)
 {
 return new String( outBuff, 0, e );
 } // end catch

 } // end else: don't compress

 } // end encodeBytes





/* ******** 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.
 *
 *
 * @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
 * @return the number of decoded bytes converted
 * @since 1.3
 */
 private static int decode4to3( byte[] source, int srcOffset, byte[] destination, int destOffset )
 {
 // 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
 {
 try{
 // 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;
 }catch( Exception e){
 System.out.println(""+source[srcOffset]+ ": " + ( DECODABET[ source[ srcOffset ] ] ) );
 System.out.println(""+source[srcOffset+1]+ ": " + ( DECODABET[ source[ srcOffset + 1 ] ] ) );
 System.out.println(""+source[srcOffset+2]+ ": " + ( DECODABET[ source[ srcOffset + 2 ] ] ) );
 System.out.println(""+source[srcOffset+3]+ ": " + ( DECODABET[ source[ srcOffset + 3 ] ] ) );
 return -1;
 } //e nd catch
 }
 } // end decodeToBytes




 /**
 * Very low-level access to decoding ASCII characters in
 * the form of a byte array. Does not support automatically
 * gunzipping or any other "fancy" features.
 *
 * @param source The Base64 encoded data
 * @param off The offset of where to begin decoding
 * @param len The length of characters to decode
 * @return decoded data
 * @since 1.3
 */
 public static byte[] decode( byte[] source, int off, int len )
 {
 int len34 = len * 3 / 4;
 byte[] outBuff = new byte[ len34 ]; // Upper limit on size of output
 int outBuffPosn = 0;

 byte[] b4 = new byte[4];
 int b4Posn = 0;
 int i = 0;
 byte sbiCrop = 0;
 byte sbiDecode = 0;
 for( i = off; i < off+len; i++ )
 {
 sbiCrop = (byte)(source[i] & 0x7f); // Only the low seven bits
 sbiDecode = DECODABET[ sbiCrop ];

 if( sbiDecode >= WHITE_SPACE_ENC ) // White space, Equals sign or better
 {
 if( sbiDecode >= EQUALS_SIGN_ENC )
 {
 b4[ b4Posn++ ] = sbiCrop;
 if( b4Posn > 3 )
 {
 outBuffPosn += decode4to3( b4, 0, outBuff, outBuffPosn );
 b4Posn = 0;

 // If that was the equals sign, break out of 'for' loop
 if( sbiCrop == EQUALS_SIGN )
 break;
 } // end if: quartet built

 } // end if: equals sign or better

 } // end if: white space, equals sign or better
 else
 {
 System.err.println( "Bad Base64 input character at " + i + ": " + source[i] + "(decimal)" );
 return null;
 } // 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
 * @since 1.4
 */
 public static byte[] decode( String s )
 {
 byte[] bytes;
 try
 {
 bytes = s.getBytes( PREFERRED_ENCODING );
 } // end try
 catch( java.io.UnsupportedEncodingException uee )
 {
 bytes = s.getBytes();
 } // end catch
 //</change>

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


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

 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 )
 {
 // 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 <tt>null</tt> if there was an error.
 *
 * @param encodedObject The Base64 data to decode
 * @return The decoded and deserialized object
 * @since 1.5
 */
 public static Object decodeToObject( String encodedObject )
 {
 // Decode and gunzip if necessary
 byte[] objBytes = decode( encodedObject );

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

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

 obj = ois.readObject();
 } // end try
 catch( java.io.IOException e )
 {
 e.printStackTrace();
 obj = null;
 } // end catch
 catch( java.lang.ClassNotFoundException e )
 {
 e.printStackTrace();
 obj = null;
 } // 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.
 *
 * @param dataToEncode byte array of data to encode in base64 form
 * @param filename Filename for saving encoded data
 * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
 *
 * @since 2.1
 */
 public static boolean encodeToFile( byte[] dataToEncode, String filename )
 {
 boolean success = false;
 Base64.OutputStream bos = null;
 try
 {
 bos = new Base64.OutputStream(
 new java.io.FileOutputStream( filename ), Base64.ENCODE );
 bos.write( dataToEncode );
 success = true;
 } // end try
 catch( java.io.IOException e )
 {

 success = false;
 } // end catch: IOException
 finally
 {
 try{ bos.close(); } catch( Exception e ){}
 } // end finally

 return success;
 } // end encodeToFile


 /**
 * Convenience method for decoding data to a file.
 *
 * @param dataToDecode Base64-encoded data as a string
 * @param filename Filename for saving decoded data
 * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
 *
 * @since 2.1
 */
 public static boolean decodeToFile( String dataToDecode, String filename )
 {
 boolean success = false;
 Base64.OutputStream bos = null;
 try
 {
 bos = new Base64.OutputStream(
 new java.io.FileOutputStream( filename ), Base64.DECODE );
 bos.write( dataToDecode.getBytes( PREFERRED_ENCODING ) );
 success = true;
 } // end try
 catch( java.io.IOException e )
 {
 success = false;
 } // end catch: IOException
 finally
 {
 try{ bos.close(); } catch( Exception e ){}
 } // end finally

 return success;
 } // end decodeToFile




 /**
 * Convenience method for reading a base64-encoded
 * file and decoding it.
 *
 * @param filename Filename for reading encoded data
 * @return decoded byte array or null if unsuccessful
 *
 * @since 2.1
 */
 public static byte[] decodeFromFile( String filename )
 {
 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 )
 {
 System.err.println( "File is too big for this convenience method (" + file.length() + " bytes)." );
 return null;
 } // 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;

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

 } // end try
 catch( java.io.IOException e )
 {
 System.err.println( "Error decoding from file " + filename );
 } // end catch: 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.
 *
 * @param filename Filename for reading binary data
 * @return base64-encoded string or null if unsuccessful
 *
 * @since 2.1
 */
 public static String encodeFromFile( String filename )
 {
 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[ (int)(file.length() * 1.4) ];
 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;

 // Save in a variable to return
 encodedData = new String( buffer, 0, length, Base64.PREFERRED_ENCODING );

 } // end try
 catch( java.io.IOException e )
 {
 System.err.println( "Error encoding from file " + filename );
 } // end catch: IOException
 finally
 {
 try{ bis.close(); } catch( Exception e) {}
 } // end finally

 return encodedData;
 } // end encodeFromFile




 /* ******** 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
 * <tt>java.io.InputStream</tt>, given in the constructor,
 * and encode/decode to/from Base64 notation on the fly.
 *
 * @see Base64
 * @since 1.3
 */
 public static class InputStream extends java.io.FilterInputStream
 {
 private boolean encode; // Encoding or decoding
 private int position; // Current position in the buffer
 private byte[] buffer; // Small buffer holding converted data
 private int bufferLength; // Length of buffer (3 or 4)
 private int numSigBytes; // Number of meaningful bytes in the buffer
 private int lineLength;
 private boolean breakLines; // Break lines at less than 80 characters


 /**
 * Constructs a {@link Base64.InputStream} in DECODE mode.
 *
 * @param in the <tt>java.io.InputStream</tt> 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.
 * 
 * Valid options:<pre>
 * ENCODE or DECODE: Encode or Decode as data is read.
 * DONT_BREAK_LINES: don't break lines at 76 characters
 * (only meaningful when encoding)
 * Note: Technically, this makes your encoding non-compliant.
 * </pre>
 * 
 * Example: <code>new Base64.InputStream( in, Base64.DECODE )</code>
 *
 *
 * @param in the <tt>java.io.InputStream</tt> from which to read data.
 * @param options Specified options
 * @see Base64#ENCODE
 * @see Base64#DECODE
 * @see Base64#DONT_BREAK_LINES
 * @since 2.0
 */
 public InputStream( java.io.InputStream in, int options )
 {
 super( in );
 this.breakLines = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
 this.encode = (options & ENCODE) == ENCODE;
 this.bufferLength = encode ? 4 : 3;
 this.buffer = new byte[ bufferLength ];
 this.position = -1;
 this.lineLength = 0;
 } // end constructor

 /**
 * Reads enough of the input stream to convert
 * to/from Base64 and returns the next byte.
 *
 * @return next byte
 * @since 1.3
 */
 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++ )
 {
 try
 {
 int b = in.read();

 // If end of stream, b is -1.
 if( b >= 0 )
 {
 b3[i] = (byte)b;
 numBinaryBytes++;
 } // end if: not end of stream

 } // end try: read
 catch( java.io.IOException e )
 {
 // Only a problem if we got no data at all.
 if( i == 0 )
 throw e;

 } // end catch
 } // end for: each needed input byte

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

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

 if( i == 4 )
 {
 numSigBytes = decode4to3( b4, 0, buffer, 0 );
 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;

 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;

 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
 {
 // When JDK1.4 is more accepted, use an assertion here.
 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
 */
 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 && i == 0 )
 // return -1;

 if( b >= 0 )
 dest[off + i] = (byte)b;
 else if( i == 0 )
 return -1;
 else
 break; // 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
 * <tt>java.io.OutputStream</tt>, given in the constructor,
 * and encode/decode to/from Base64 notation on the fly.
 *
 * @see Base64
 * @since 1.3
 */
 public static class OutputStream extends java.io.FilterOutputStream
 {
 private boolean encode;
 private int position;
 private byte[] buffer;
 private int bufferLength;
 private int lineLength;
 private boolean breakLines;
 private byte[] b4; // Scratch used in a few places
 private boolean suspendEncoding;

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


 /**
 * Constructs a {@link Base64.OutputStream} in
 * either ENCODE or DECODE mode.
 * 
 * Valid options:<pre>
 * ENCODE or DECODE: Encode or Decode as data is read.
 * DONT_BREAK_LINES: don't break lines at 76 characters
 * (only meaningful when encoding)
 * Note: Technically, this makes your encoding non-compliant.
 * </pre>
 * 
 * Example: <code>new Base64.OutputStream( out, Base64.ENCODE )</code>
 *
 * @param out the <tt>java.io.OutputStream</tt> to which data will be written.
 * @param options Specified options.
 * @see Base64#ENCODE
 * @see Base64#DECODE
 * @see Base64#DONT_BREAK_LINES
 * @since 1.3
 */
 public OutputStream( java.io.OutputStream out, int options )
 {
 super( out );
 this.breakLines = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
 this.encode = (options & ENCODE) == ENCODE;
 this.bufferLength = encode ? 3 : 4;
 this.buffer = new byte[ bufferLength ];
 this.position = 0;
 this.lineLength = 0;
 this.suspendEncoding = false;
 this.b4 = new byte[4];
 } // 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
 */
 public void write(int theByte) throws java.io.IOException
 {
 // Encoding suspended?
 if( suspendEncoding )
 {
 super.out.write( theByte );
 return;
 } // end if: supsended

 // Encode?
 if( encode )
 {
 buffer[ position++ ] = (byte)theByte;
 if( position >= bufferLength ) // Enough to encode.
 {
 out.write( encode3to4( b4, buffer, bufferLength ) );

 lineLength += 4;
 if( breakLines && lineLength >= MAX_LINE_LENGTH )
 {
 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 );
 out.write( b4, 0, len );
 //out.write( Base64.decode4to3( buffer ) );
 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
 */
 public void write( byte[] theBytes, int off, int len ) throws java.io.IOException
 {
 // Encoding suspended?
 if( suspendEncoding )
 {
 super.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.
 */
 public void flushBase64() throws java.io.IOException
 {
 if( position > 0 )
 {
 if( encode )
 {
 out.write( encode3to4( b4, buffer, position ) );
 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
 */
 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
 * base640-encoded data in a stream.
 *
 * @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
 * base640-encoded data in a stream.
 *
 * @since 1.5.1
 */
 public void resumeEncoding()
 {
 this.suspendEncoding = false;
 } // end resumeEncoding



 } // end inner class OutputStream


} // end class Base64

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