Encodes and decodes to and from Base64 notation.
//package org.nex.util;
/**
* Encodes and decodes to and from Base64 notation.
*
* <p>
* Change Log:
* </p>
* <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>
*
* <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 2.1
*/
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>.
* <p>
* Valid options:<pre>
* GZIP: gzip-compresses object before encoding it.
* DONT_BREAK_LINES: don't break lines at 76 characters
* <i>Note: Technically, this makes your encoding non-compliant.</i>
* </pre>
* <p>
* Example: <code>encodeObject( myObj, Base64.GZIP )</code> or
* <p>
* 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.
* <p>
* Valid options:<pre>
* GZIP: gzip-compresses object before encoding it.
* DONT_BREAK_LINES: don't 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.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.
* <p>
* Valid options:<pre>
* GZIP: gzip-compresses object before encoding it.
* DONT_BREAK_LINES: don't 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.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.
* <p>
* 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)
* <i>Note: Technically, this makes your encoding non-compliant.</i>
* </pre>
* <p>
* Example: <code>new Base64.InputStream( in, Base64.DECODE )</code>
*
*
* @param in the <tt>java.io.InputStream</tt> from which to read data.
* @param options Specified options
* @see Base64#ENCODE
* @see Base64#DECODE
* @see Base64#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.
* <p>
* 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)
* <i>Note: Technically, this makes your encoding non-compliant.</i>
* </pre>
* <p>
* Example: <code>new Base64.OutputStream( out, Base64.ENCODE )</code>
*
* @param out the <tt>java.io.OutputStream</tt> to which data will be written.
* @param options Specified options.
* @see Base64#ENCODE
* @see Base64#DECODE
* @see Base64#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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