* @param dest array to hold values
         * @param off offset for array
         * @param len max number of bytes to read into array
         * @return bytes read into array or -1 if end of stream is encountered.
         * @since 1.3
         */
        @Override
        public int read( byte[] dest, int off, int len ) 
        throws java.io.IOException {
            int i;
            int b;
            for( i = 0; i < len; i++ ) {
                b = read();
                
                if( b >= 0 ) {
                    dest[off + i] = (byte) b;
                }
                else if( i == 0 ) {
                    return -1;
                }
                else {
                    break; // Out of 'for' loop
                } // Out of 'for' loop
            }   // end for: each byte read
            return i;
        }   // end read
        
    }   // end inner class InputStream
    
    
    
    
    
    
    /* ********  I N N E R   C L A S S   O U T P U T S T R E A M  ******** */
    
    
    
    /**
     * A {@link Base64.OutputStream} will write data to another
     * <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;
        private int     options;    // Record for later
        private byte[]  decodabet;  // Local copies to avoid extra method calls
        
        /**
         * Constructs a {@link Base64.OutputStream} in ENCODE mode.
         *
         * @param out the <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.
         *   DO_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)</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#DO_BREAK_LINES
         * @since 1.3
         */
        public OutputStream( java.io.OutputStream out, int options ) {
            super( out );
            this.breakLines   = (options & DO_BREAK_LINES) != 0;
            this.encode       = (options & ENCODE) != 0;
            this.bufferLength = encode ? 3 : 4;
            this.buffer       = new byte[ bufferLength ];
            this.position     = 0;
            this.lineLength   = 0;
            this.suspendEncoding = false;
            this.b4           = new byte[4];
            this.options      = options;
            this.decodabet    = getDecodabet(options);
        }   // end constructor
        
        
        /**
         * Writes the byte to the output stream after
         * converting to/from Base64 notation.
         * When encoding, bytes are buffered three
         * at a time before the output stream actually
         * gets a write() call.
         * When decoding, bytes are buffered four
         * at a time.
         *
         * @param theByte the byte to write
         * @since 1.3
         */
        @Override
        public void write(int theByte) 
        throws java.io.IOException {
            // Encoding suspended?
            if( suspendEncoding ) {
                this.out.write( theByte );
                return;
            }   // end if: supsended
            
            // Encode?
            if( encode ) {
                buffer[ position++ ] = (byte)theByte;
                if( position >= bufferLength ) { // Enough to encode.
                
                    this.out.write( encode3to4( b4, buffer, bufferLength, options ) );

                    lineLength += 4;
                    if( breakLines && lineLength >= MAX_LINE_LENGTH ) {
                        this.out.write( NEW_LINE );
                        lineLength = 0;
                    }   // end if: end of line

                    position = 0;
                }   // end if: enough to output
            }   // end if: encoding

            // Else, Decoding
            else {
                // Meaningful Base64 character?
                if( decodabet[ theByte & 0x7f ] > WHITE_SPACE_ENC ) {
                    buffer[ position++ ] = (byte)theByte;
                    if( position >= bufferLength ) { // Enough to output.
                    
                        int len = Base64.decode4to3( buffer, 0, b4, 0, options );
                        out.write( b4, 0, len );
                        position = 0;
                    }   // end if: enough to output
                }   // end if: meaningful base64 character
                else if( decodabet[ theByte & 0x7f ] != WHITE_SPACE_ENC ) {
                    throw new java.io.IOException( "Invalid character in Base64 data." );
                }   // end else: not white space either
            }   // end else: decoding
        }   // end write
        
        
        
        /**
         * Calls {@link #write(int)} repeatedly until <var>len</var> 
         * bytes are written.
         *
         * @param theBytes array from which to read bytes
         * @param off offset for array
         * @param len max number of bytes to read into array
         * @since 1.3
         */
        @Override
        public void write( byte[] theBytes, int off, int len ) 
        throws java.io.IOException {
            // Encoding suspended?
            if( suspendEncoding ) {
                this.out.write( theBytes, off, len );
                return;
            }   // end if: supsended
            
            for( int i = 0; i < len; i++ ) {
                write( theBytes[ off + i ] );
            }   // end for: each byte written
            
        }   // end write
        
        
        
        /**
         * Method added by PHIL. [Thanks, PHIL. -Rob]
         * This pads the buffer without closing the stream.
         * @throws java.io.IOException  if there's an error.
         */
        public void flushBase64() throws java.io.IOException  {
            if( position > 0 ) {
                if( encode ) {
                    out.write( encode3to4( b4, buffer, position, options ) );
                    position = 0;
                }   // end if: encoding
                else {
                    throw new java.io.IOException( "Base64 input not properly padded." );
                }   // end else: decoding
            }   // end if: buffer partially full

        }   // end flush

        
        /** 
         * Flushes and closes (I think, in the superclass) the stream. 
         *
         * @since 1.3
         */
        @Override
        public void close() throws java.io.IOException {
            // 1. Ensure that pending characters are written
            flushBase64();

            // 2. Actually close the stream
            // Base class both flushes and closes.
            super.close();
            
            buffer = null;
            out    = null;
        }   // end close
        
        
        
        /**
         * Suspends encoding of the stream.
         * May be helpful if you need to embed a piece of
         * base64-encoded data in a stream.
         *
         * @throws java.io.IOException  if there's an error flushing
         * @since 1.5.1
         */
        public void suspendEncoding() throws java.io.IOException  {
            flushBase64();
            this.suspendEncoding = true;
        }   // end suspendEncoding
        
        
        /**
         * Resumes encoding of the stream.
         * May be helpful if you need to embed a piece of
         * base64-encoded data in a stream.
         *
         * @since 1.5.1
         */
        public void resumeEncoding() {
            this.suspendEncoding = false;
        }