question: static final void encode ( byte [ ] src , int srcOff , int len , byte [ ] dst , int dstOff ) { dst [ dstOff ] = ( byte ) ENCODE_TABLE . charAt ( ( src [ srcOff ] > > 2 ) & 0x3F ) ; if ( len == 3 ) { dst [ dstOff + 1 ] = ( byte ) ENCODE_TABLE . charAt ( ( ( src [ srcOff ] << 4 ) & 0x30 ) | ( ( src [ srcOff + 1 ] > > 4 ) & 0x0F ) ) ; dst [ dstOff + 2 ] = ( byte ) ENCODE_TABLE . charAt ( ( ( src [ srcOff + 1 ] << 2 ) & 0x3C ) | ( ( src [ srcOff + 2 ] > > 6 ) & 0x03 ) ) ; dst [ dstOff + 3 ] = ( byte ) ENCODE_TABLE . charAt ( src [ srcOff + 2 ] & 0x3F ) ; } else if ( len == 2 ) { dst [ dstOff + 1 ] = ( byte ) ENCODE_TABLE . charAt ( ( ( src [ srcOff ] << 4 ) & 0x30 ) | ( ( src [ srcOff + 1 ] > > 4 ) & 0x0F ) ) ; dst [ dstOff + 2 ] = ( byte ) ENCODE_TABLE . charAt ( ( src [ srcOff + 1 ] << 2 ) & 0x3C ) ; } else { dst [ dstOff + 1 ] = ( byte ) ENCODE_TABLE . charAt ( ( src [ srcOff ] << 4 ) & 0x30 ) ; } }
target:  Encode len bytes of data in src at offset srcOff, storing the result into dst at offset dstOff. len must be 1, 2, or 3. dst must have at least len+1 bytes of space at dstOff. src and dst should not be the same object. This method does no validation of the input values in the interest of performance.