📄 105d06f36c36001b19ca9d8cdf62cf01
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* Simple helper method that Base64-encodes data to a file.
*
* @param rawdata The data to write.
* @param file The file to read.
* @return Whether or not the write was a success.
* @since 1.4
*/
public static boolean encodeToFile( byte[] rawdata, String file )
{
return writeFile( rawdata, file, ENCODE );
} // end encodeFromFile
/**
* Simple helper method that Base64-decodes data to a file.
*
* @param encdata The data to write.
* @param file The file to read.
* @return Whether or not the write was a success.
* @since 1.4
*/
public static boolean decodeToFile( byte[] encdata, String file )
{
return writeFile( encdata, file, DECODE );
} // end encodeFromFile
/* ******** 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
*/
private 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
*/
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
/**
* 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
{
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
/* ******** 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
private int lineLength;
private boolean breakLines; // Break lines at less than 80 characters
/**
* 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, Base64.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 )
{
this( in, encode, true );
} // 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
* @param breakLines Break lines at less than 80 characters.
* @see Base64#ENCODE
* @see Base64#DECODE
* @since 1.3
*/
public InputStream( java.io.InputStream in, boolean encode, boolean breakLines )
{
super( in );
this.breakLines = breakLines;
this.encode = encode;
this.bufferLength = encode ? 4 : 3;
this.buffer = new byte[ bufferLength ];
this.position = -1;
this.lineLength = 0;
} // end constructor
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