生成随机字符串

/**
 * 生成随机字符串
 * @param str 字符池
 * @param length 随机字符串长度
 * @return 生成的随机字符串
 */
public static String randomString(int length,String str) {
    //字符池
     str = "0EkFaGlH1ImJbKnL2MoNcOpP3QqRdSrT4UsVeWtX5YuZfv6wgx7yhz8AiB9CjD";
    //结果
    StringBuffer result = new StringBuffer();
    for (int i = 0; i < length; i++) {
        int index = (int) (Math.random() * str.length());
        result.append(str.charAt(index));
    }
    return result.toString();
}