class Runes {


    private Runes() {
    }

//    public static void main(final String[] args) {
//        System.out.println(getChinesePercent("123abc这个中文cde123abc也要提取123ab"));
//    }

    /**
     * Removes control characters for the specified string.
     *
     * @param str the specified string
     * @return str removed control characters
     */
    public static String removeControlChars(final String str) {
        final CharMatcher charsToPreserve = CharMatcher.anyOf("\r\n\t");
        final CharMatcher allButPreserved = charsToPreserve.negate();
        final CharMatcher controlCharactersToRemove = CharMatcher.javaIsoControl().and(allButPreserved);

        return controlCharactersToRemove.removeFrom(str);
    }

    /**
     * Gets chinese percentage of the specified string.
     *
     * @param str the specified string
     * @return percentage
     */
    public static int getChinesePercent(final String str) {<FILL_FUNCTION_BODY>}
}

        if (StringUtils.isBlank(str)) {
            return 0;
        }

        final Pattern p = Pattern.compile("([\u4e00-\u9fa5]+)");
        final Matcher m = p.matcher(str);
        final StringBuilder chineseBuilder = new StringBuilder();
        while (m.find()) {
            chineseBuilder.append(m.group(0));
        }

        return (int) Math.floor(StringUtils.length(chineseBuilder.toString()) / (double) StringUtils.length(str) * 100);
    
<no_super_class>