/*
* LinShare is an open source filesharing software, part of the LinPKI software
* suite, developed by Linagora.
*
* Copyright (C) 2015 LINAGORA
*
* This program is free software: you can redistribute it and/or modify it under
* the terms of the GNU Affero General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any
* later version, provided you comply with the Additional Terms applicable for
* LinShare software by Linagora pursuant to Section 7 of the GNU Affero General
* Public License, subsections (b), (c), and (e), pursuant to which you must
* notably (i) retain the display of the “LinShare™” trademark/logo at the top
* of the interface window, the display of the “You are using the Open Source
* and free version of LinShare™, powered by Linagora © 2009–2015. Contribute to
* Linshare R&D by subscribing to an Enterprise offer!” infobox and in the
* e-mails sent with the Program, (ii) retain all hypertext links between
* LinShare and linshare.org, between linagora.com and Linagora, and (iii)
* refrain from infringing Linagora intellectual property rights over its
* trademarks and commercial brands. Other Additional Terms apply, see
* <http://www.linagora.com/licenses/> for more details.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
* details.
*
* You should have received a copy of the GNU Affero General Public License and
* its applicable Additional Terms for LinShare along with this program. If not,
* see <http://www.gnu.org/licenses/> for the GNU Affero General Public License
* version 3 and <http://www.linagora.com/licenses/> for the Additional Terms
* applicable to LinShare software.
*/
/**
* <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/xmlizable">http://iharder.net/xmlizable</a>
* periodically to check for updates or to contribute improvements.
* </p>
*
* @author Robert Harder
* @author rharder@usa.net
* @version 1.3
*/
// Import this class into LinShare project.
package org.linagora.linshare.core.utils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class Base64Utils
{
private static final Log LOGGER = LogFactory.getLog(Base64Utils.class);
/** Specify encoding (value is <tt>true</tt>). */
public final static boolean ENCODE = true;
/** Specify decoding (value is <tt>false</tt>). */
public final static boolean DECODE = false;
/** Maximum line length (76) of Base64 output. */
public 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';
/** The 64 valid Base64 values. */
private final static byte[] 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[] 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 */
};
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 Base64Utils(){}
/** Testing. */
public static void main( String[] args )
{
String s = "Hello, world";
s = "abcd";
//s = System.getProperties().toString();
//System.out.println( s + ": \n [" + encode( s ) + "]\n [" + decode(encode(s)) + "]" );
byte[] b = encodeString(s).getBytes();
byte[] c = decode( b, 0, b.length );
if(LOGGER.isDebugEnabled()){
LOGGER.debug( "\n\n" + s + ":" + new String(b) + ":" + new String(c) );
}
try
{
java.io.FileInputStream fis = new java.io.FileInputStream( "c:\\abcd.txt" );
Base64Utils.InputStream b64is = new Base64Utils.InputStream( fis, DECODE );
int ib = 0;
if(LOGGER.isDebugEnabled()){
while( (ib = b64is.read()) > 0 )
{
LOGGER.debug( new String( ""+(char)ib ) );
}
}
} // end try
catch( Exception e)
{ e.printStackTrace();
}
}
/* ******** E N C O D I N G M E T H O D S ******** */
/**
* Encodes the first three bytes of array <var>threeBytes</var>
* and returns a four-byte array in Base64 notation.
*
* @param threeBytes the array to convert
* @return four byte array in Base64 notation.
* @since 1.3
*/
public static byte[] encode3to4( byte[] threeBytes )
{ return encode3to4( threeBytes, 3 );
} // end encodeToBytes
/**
* 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>.
*
* @param threeBytes the array to convert
* @param numSigBytes the number of significant bytes in your array
* @return four byte array in Base64 notation.
* @since 1.3
*/
public static byte[] encode3to4( byte[] threeBytes, int numSigBytes )
{ byte[] dest = new byte[4];
encode3to4( threeBytes, 0, numSigBytes, dest, 0 );
return dest;
}
/**
* 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
*/
public 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>.
*
* @param serializableObject The object to encode
* @return The Base64-encoded object
* @since 1.4
*/
public static String encodeObject( java.io.Serializable serializableObject )
{
java.io.ByteArrayOutputStream baos = null;
java.io.OutputStream b64os = null;
java.io.ObjectOutputStream oos = null;
try
{
baos = new java.io.ByteArrayOutputStream();
b64os = new Base64Utils.OutputStream( baos, Base64Utils.ENCODE );
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{ b64os.close(); } catch( Exception e ){}
try{ baos.close(); } catch( Exception e ){}
} // end finally
return new String( baos.toByteArray() );
} // end encode
/**
* Encodes a byte array into Base64 notation.
* Equivalen to calling
* <code>encodeBytes( source, 0, source.length )</code>
*
* @param source The data to convert
* @since 1.4
*/
public static String encodeBytes( byte[] source )
{ return encodeBytes( source, 0, source.length );
} // end encodeBytes
/**
* Encodes a byte array into Base64 notation.
*
* @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 )
{
int len43 = len * 4 / 3;
byte[] outBuff = new byte[ ( len43 ) // Main 4:3
+ ( (len % 3) > 0 ? 4 : 0 ) // Account for padding
+ ( len43 / MAX_LINE_LENGTH ) ]; // 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, 3, outBuff, e );
lineLength += 4;
if( 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, len - d, outBuff, e );
e += 4;
} // end if: some padding needed
return new String( outBuff, 0, e );
} // end encodeBytes
/**
* Encodes a string in Base64 notation with line breaks
* after every 75 Base64 characters.
*
* @param s the string to encode
* @return the encoded string
* @since 1.3
*/
public static String encodeString( String s )
{ return encodeBytes( s.getBytes() );
} // end encodeString
/* ******** D E C O D I N G M E T H O D S ******** */
/**
* Decodes the first four bytes of array <var>fourBytes</var>
* and returns an array up to three bytes long with the
* decoded values.
*
* @param fourBytes the array with Base64 content
* @return array with decoded values
* @since 1.3
*/
public static byte[] decode4to3( byte[] fourBytes )
{
byte[] outBuff1 = new byte[3];
int count = decode4to3( fourBytes, 0, outBuff1, 0 );
byte[] outBuff2 = new byte[ count ];
for( int i = 0; i < count; i++ )
outBuff2[i] = outBuff1[i];
return outBuff2;
}
/**
* 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
*/
public static int decode4to3( byte[] source, int srcOffset, byte[] destination, int destOffset )
{
// Example: Dk==
if( source[ srcOffset + 2] == EQUALS_SIGN )
{
int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
| ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
destination[ destOffset ] = (byte)( outBuff >>> 16 );
return 1;
}
// Example: DkL=
else if( source[ srcOffset + 3 ] == EQUALS_SIGN )
{
int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
| ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
| ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
destination[ destOffset ] = (byte)( outBuff >>> 16 );
destination[ destOffset + 1 ] = (byte)( outBuff >>> 8 );
return 2;
}
// Example: DkLE
else
{
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 );
destination[ destOffset ] = (byte)( outBuff >> 16 );
destination[ destOffset + 1 ] = (byte)( outBuff >> 8 );
destination[ destOffset + 2 ] = (byte)( outBuff );
return 3;
}
} // end decodeToBytes
/**
* Decodes data from Base64 notation.
*
* @param s the string to decode
* @return the decoded data
* @since 1.4
*/
public static byte[] decode( String s )
{
byte[] bytes = s.getBytes();
return decode( bytes, 0, bytes.length );
} // end decode
/**
* Decodes data from Base64 notation and
* returns it as a string.
* Equivlaent to calling
* <code>new String( decode( s ) )</code>
*
* @param s the strind to decode
* @return The data as a string
* @since 1.4
*/
public static String decodeToString( String s )
{ return new String( decode( s ) );
} // end decodeToString
/**
* Attempts to decode Base64 data and deserialize a Java
* Object within. Returns <tt>null if there was an error.
*
* @param encodedObject The Base64 data to decode
* @return The decoded and deserialized object
* @since 1.4
*/
public static Object decodeToObject( String encodedObject )
{
byte[] objBytes = decode( encodedObject );
java.io.ByteArrayInputStream bais = null;
java.io.ObjectInputStream ois = null;
try
{
bais = new java.io.ByteArrayInputStream( objBytes );
ois = new java.io.ObjectInputStream( bais );
return ois.readObject();
} // end try
catch( java.io.IOException e )
{
e.printStackTrace();
return null;
} // end catch
catch( java.lang.ClassNotFoundException e )
{
e.printStackTrace();
return null;
} // end catch
finally
{
try{ bais.close(); } catch( Exception e ){}
try{ ois.close(); } catch( Exception e ){}
} // end finally
} // end decodeObject
/**
* Decodes Base64 content in byte array format and returns
* the decoded byte array.
*
* @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 = 0; i < 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
{
LOGGER.error( "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
/* ******** 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
* {@link java.io.InputStream}, given in the constructor,
* and encode/decode to/from Base64 notation on the fly.
*
* @see Base64
* @see java.io.FilterInputStream
* @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
/**
* Constructs a {@link Base64#InputStream} in DECODE mode.
*
* @param in the {@link java.io.InputStream} from which to read data.
* @since 1.3
*/
public InputStream( java.io.InputStream in )
{ this( in, Base64Utils.DECODE );
} // end constructor
/**
* Constructs a {@link Base64#InputStream} in
* either ENCODE or DECODE mode.
*
* @param in the {@link java.io.InputStream} from which to read data.
* @param encode Conversion direction
* @see Base64#ENCODE
* @see Base64#DECODE
* @since 1.3
*/
public InputStream( java.io.InputStream in, boolean encode )
{
super( in );
this.encode = encode;
this.bufferLength = encode ? 4 : 3;
this.buffer = new byte[ bufferLength ];
this.position = -1;
} // 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];
numSigBytes = 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;
numSigBytes++;
} // 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( numSigBytes > 0 )
{
encode3to4( b3, 0, numSigBytes, buffer, 0 );
position = 0;
} // end if: got data
} // end if: encoding
// Else decoding
else
{
byte[] b4 = new byte[4];
int i = 0;
for( i = 0; i < 4; i++ )
{
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
} // end else: decode
} // end else: get data
// Got data?
if( position >= 0 )
{
// End of relevant data?
if( position >= numSigBytes )
return -1;
int b = buffer[ position++ ];
if( position >= bufferLength )
position = -1;
return b;
} // end if: position >= 0
// Else error
else
return -1;
} // 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 )
return -1;
dest[off + i] = (byte)b;
} // 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
* {@link java.io.OutputStream}, given in the constructor,
* and encode/decode to/from Base64 notation on the fly.
*
* @see Base64
* @see java.io.FilterOutputStream
* @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;
/**
* Constructs a {@link Base64#OutputStream} in ENCODE mode.
*
* @param out the {@link java.io.OutputStream} to which data will be written.
* @since 1.3
*/
public OutputStream( java.io.OutputStream out )
{ this( out, Base64Utils.ENCODE );
} // end constructor
/**
* Constructs a {@link Base64#OutputStream} in
* either ENCODE or DECODE mode.
*
* @param out the {@link java.io.OutputStream} to which data will be written.
* @param encode Conversion direction
* @see Base64#ENCODE
* @see Base64#DECODE
* @since 1.3
*/
public OutputStream( java.io.OutputStream out, boolean encode )
{
super( out );
this.encode = encode;
this.bufferLength = encode ? 3 : 4;
this.buffer = new byte[ bufferLength ];
this.position = 0;
this.lineLength = 0;
} // 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
{
buffer[ position++ ] = (byte)theByte;
if( position >= bufferLength )
{
if( encode )
{
out.write( Base64Utils.encode3to4( buffer, bufferLength ) );
lineLength += 4;
if( lineLength >= MAX_LINE_LENGTH )
{
out.write( NEW_LINE );
lineLength = 0;
} // end if: end o fline
} // end if: encoding
else
out.write( Base64Utils.decode4to3( buffer ) );
position = 0;
} // end if: convert and flush
} // end write
/**
* Calls {@link #write} 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
{
for( int i = 0; i < len; i++ )
{
write( theBytes[ off + i ] );
} // end for: each byte written
} // end write
/**
* Appropriately pads Base64 notation when encoding
* or throws an exception if Base64 input is not
* properly padded when decoding.
*
* @since 1.3
*/
public void flush() throws java.io.IOException
{
if( position > 0 )
{
if( encode )
{
out.write( Base64Utils.encode3to4( buffer, position ) );
} // end if: encoding
else
{
throw new java.io.IOException( "Base64 input not properly padded." );
} // end else: decoding
} // end if: buffer partially full
super.flush();
out.flush();
} // end flush
/**
* Flushes and closes stream.
*
* @since 1.3
*/
public void close() throws java.io.IOException
{
this.flush();
super.close();
out.close();
buffer = null;
out = null;
} // end close
} // end inner class OutputStream
} // end class Base64