private static final String CODE = "0123456789";    /**     * 生成随机字符，不含0和O，字符全为大写     *      * @param length     * @return     */    public static String getCaptachCode(int length) {        String str = "";        for (int i = 0; i < length; i++) {            str = str + CODE.charAt((int) (CODE.length() * java.lang.Math.random()));        }        return str;    }