Review

class StringEscapeUtils {
    /**
     * <p>Returns a <code>String</code> value for an unescaped CSV column. </p>
     *
     * <p>If the value is enclosed in double quotes, and contains a comma, newline 
     *    or double quote, then quotes are removed. 
     * </p>
     *
     * <p>Any double quote escaped characters (a pair of double quotes) are unescaped 
     *    to just one double quote. </p>
     *
     * <p>If the value is not enclosed in double quotes, or is and does not contain a 
     *    comma, newline or double quote, then the String value is returned unchanged.</p>
     * </p>
     *
     * see <a href="http://en.wikipedia.org/wiki/Comma-separated_values">Wikipedia</a> and
     * <a href="http://tools.ietf.org/html/rfc4180">RFC 4180</a>.
     *
     * @param str the input CSV column String, may be null
     * @param out Writer to write the input String to, with enclosing double quotes 
     * removed and embedded double quotes unescaped, <code>null</code> if null string input
     * @throws IOException if error occurs on underlying Writer
     * @since 2.4
     */
    public static void unescapeCsv(Writer out, String str) throws IOException {
        if (str == null) {
            return;
        }
        if (str.length() < 2) {
            out.write(str);
            return;
        }
        if ( str.charAt(0) != CSV_QUOTE || str.charAt(str.length() - 1) != CSV_QUOTE ) {
            out.write(str);
            return;
        }

        // strip quotes
        String quoteless = str.substring(1, str.length() - 1);

        if ( StringUtils.containsAny(quoteless, CSV_SEARCH_CHARS) ) {
            // deal with escaped quotes; ie) ""
            str = StringUtils.replace(quoteless, CSV_QUOTE_STR + CSV_QUOTE_STR, CSV_QUOTE_STR);
        }

        out.write(str);
    }

}