question: public static boolean isValidXmlIdentifier ( String s ) { if ( s != null ) { int len = s . length ( ) ; if ( len == 0 ) { return false ; } for ( int i = 0 ; i < len ; i ++ ) { char ch = s . charAt ( i ) ; if ( ( i == 0 && ! Character . isUnicodeIdentifierStart ( ch ) ) || ( ! Character . isUnicodeIdentifierStart ( ch ) && ! Character . isDigit ( ch ) && ! Utils . isIdentifierHelperChar ( ch ) ) ) { return false ; } } return true ; } return false ; }
target:  Checks whether specified string can be valid tag name or attribute name in xml.