public myTest{
    public static StringBuilder hhhh(String value) {
        StringBuilder sb = new StringBuilder();
        String strIndex = "";
        // String regex = "\\d*"; 可以用String 但最终结果只有后面的数字 例子中的只能显示222222222，因为会被替代
        Pattern pattern = Pattern.compile(regex);
        Matcher match = pattern.matcher(value);
        while (match.find()) {
            if (!"".equals(match.group()))
                 sb.append(match.group());
        }
        return sb;
    }

    public static void main(String[] args) {
        String str = "xxxxgggggg2222222[1111uuuuuuuuuu222222222";
        System.out.println(hhhh(str));
    }
}

执行结果：