question: public static String quoteIdentifier ( String s ) { if ( s == null || s . length ( ) == 0 ) { return "\"\"" ; } char c = s . charAt ( 0 ) ; if ( ( ! Character . isLetter ( c ) && c != '_' ) || Character . isLowerCase ( c ) ) { return StringUtils . quoteIdentifier ( s ) ; } for ( int i = 1 , length = s . length ( ) ; i < length ; i ++ ) { c = s . charAt ( i ) ; if ( ( ! Character . isLetterOrDigit ( c ) && c != '_' ) || Character . isLowerCase ( c ) ) { return StringUtils . quoteIdentifier ( s ) ; } } if ( isKeyword ( s , true ) ) { return StringUtils . quoteIdentifier ( s ) ; } return s ; }
target:  Add double quotes around an identifier if required.