question: public static String convertFileName ( String name , int maxBytes ) { try { return convertFileName ( name , maxBytes , Charset . defaultCharset ( ) ) ; } catch ( CharacterCodingException cce ) { try { return convertFileName ( name , maxBytes , Charset . forName ( "UTF-8" ) ) ; } catch ( CharacterCodingException e ) { throw new RuntimeException ( "UTF-8 should have encoded: " + name , e ) ; } } }
target:  Cleans up the filename from illegal characters and truncates it to the length of bytes specified.