question: public static String encodeLines ( byte [ ] in , int iOff , int iLen , int lineLen , String lineSeparator ) { int blockLen = ( lineLen * 3 ) / 4 ; if ( blockLen <= 0 ) throw new IllegalArgumentException ( ) ; int lines = ( iLen + blockLen - 1 ) / blockLen ; int bufLen = ( ( iLen + 2 ) / 3 ) * 4 + lines * lineSeparator . length ( ) ; StringBuilder buf = new StringBuilder ( bufLen ) ; int ip = 0 ; while ( ip < iLen ) { int l = Math . min ( iLen - ip , blockLen ) ; buf . append ( encode ( in , iOff + ip , l ) ) ; buf . append ( lineSeparator ) ; ip += l ; } return buf . toString ( ) ; }
target:  Encodes a byte array into Base 64 format and breaks the output into lines.