public class CreateCode { private static String []str_char = {"A","B","C","D","E","F","G","H", "I","J","K","L","M","N","O","P","Q", "R","S","T","U","V","W","X","Y","Z"}; private static String one_str_max_num = "9"; private static String two_str_max_num = "9"; private static int str_max_char = 25; * 邀请码 * @param code * @return public static String getInviteCode(String code){ String newCode = ""; if (StringUtils.isEmpty(code)){ newCode = "0A0A"; }else { StringBuffer sb = new StringBuffer(); String []str_string = code.split("\\d"); String []num_string = code.split("\\D"); for (int i = 0; i < str_string.length; i++) { if (StringUtils.isEmpty(str_string[i])){ continue; sb.append(str_string[i]); if (i != str_string.length -1){ sb.append(","); str_string = sb.toString().split(","); int one_char = 0; int two_char = 0; for (int j = 0; j < str_char.length; j++) { if (str_char[j].equals(str_string[0])){ one_char = j; break; for (int j = 0; j < str_char.length; j++) { if (str_char[j].equals(str_string[1])){ two_char = j; break; one_str_max_num = "9"; two_str_max_num = "9"; for (int i = 1; i < num_string[0].length(); i++) { one_str_max_num += "9"; for (int i = 1; i < num_string[1].length(); i++) { two_str_max_num += "9"; newCode = createCode(num_string[0], one_char, num_string[1], two_char); return newCode; * 产生code * @param one_char * @param two_char * @param num_string_one * @param num_string_two * @return private static String createCode(String num_string_one, int one_char, String num_string_two, int two_char){ int one_max_num = Integer.valueOf(one_str_max_num); int two_max_num = Integer.valueOf(two_str_max_num); int one_num = Integer.valueOf(num_string_one); int two_num = Integer.valueOf(num_string_two); if (two_num < two_max_num){ two_num += 1; }else if (two_num == two_max_num && two_char < str_max_char){ two_num = 0; two_char += 1; }else if (two_num == two_max_num && two_char == str_max_char && one_num < one_max_num){ two_num = 0; two_char = 0; one_num += 1; }else if (two_num == two_max_num && two_char == str_max_char && one_num == one_max_num && one_char < str_max_char){ two_num = 0; two_char = 0; one_num = 0; one_char += 1; }else if (two_num == two_max_num && two_char == str_max_char && one_num == one_max_num && one_char == str_max_char && one_max_num == two_max_num){ two_str_max_num += "9"; two_num = 0; two_char = 0; one_num = 0; one_char = 0; return createCode(one_num + "", one_char, two_num + "", two_char); }else if (two_num > two_max_num){ for (int i = 1; i < num_string_two.length(); i++) { two_str_max_num += "9"; return createCode(one_num + "", one_char, two_num + "" , two_char); }else if (one_num > one_max_num){ for (int i = 1; i < num_string_one.length(); i++) { one_str_max_num += "9"; return createCode(one_num + "", one_char, two_num + "", two_char); }else if (two_num == two_max_num){ if (two_char == str_max_char && one_num < two_num){ one_str_max_num += "9"; one_num = 0; one_char = 0; two_num = 0; two_char = 0; return createCode(one_num + "", one_char, two_num + "", two_char); }else if (one_num == one_max_num){ if (one_char == str_max_char){ two_str_max_num += "9"; one_num = 0; one_char = 0; two_num = 0; two_char = 0; return createCode(one_num + "", one_char,two_num + "", two_char); String one_num_str = one_num + ""; String two_num_str = two_num + ""; for (int i = 1;i < one_str_max_num.length(); i++) { if (one_num < Math.pow(10, i)){ one_num_str = "0" + one_num_str; for (int i = 1;i < two_str_max_num.length(); i++) { if (two_num < Math.pow(10, i)){ two_num_str = "0" + two_num_str; String code =one_num_str + str_char[one_char] + two_num_str + str_char[two_char]; return code; public static void main(String []arg){ String code = ""; for (int i = 0;i < 100; i++) { code = getInviteCode(code); System.out.println("第"+i+"#######code#########"+code); Java生成不重复的邀请码/退换码，数字字母组合/** * 生成邀请码工具类 */public class CreateCode { private static String []str_char = {"A","B","C","D","E","F","G","H", "I","J","K","L","M","N","O","P","Q", "R","S","T","U","V","W","X","Y","Z"}; private 需要通过资料 码 ，拿到数据库中的某个文件资源 需要通过 邀请码 ，对某个用户做一些操作 这个资料 码 和 邀请码 都是随机 码 ，多位，由 数字 和 字母 组成 ，可以与整形类型的ID相互转换 网络上找到的实现方法，进行一些简单思考和更改 1. 如何保证不重复性质？ 我们发现进制数是不重复的，我们来看一下进制数 比如二进制， 二位二进制数可以表示 2^2个十进制数 [0,3] 在许多APP中，为了推广经营用户常常会有分享功能，APP内的用户拥全局 唯一 的 邀请码 ，将 邀请码 分享给自己的好友，好友按照分享的引导步骤填写 邀请码 ，邀请人就可以获得一定的奖励，那么我们在开发过程中要如何 生成 一个全局 唯一 的 邀请码 呢，下面笔者提一下自己的思路，如果有更好的解决方案，欢迎各位小伙伴一起交流。 邀请码 的 组成 现在大多数的 邀请码 由 数字 和 字母 组成 ，长度由业务需求而定，在此，笔者想要的邀... eclipse导入项目报 Unknown error: Unable to build: the file dx.jar was not loaded from the SDK folder FileNotFoundException: /storage/emulated/0/Pictures/1582: open failed: EACCES (Permission denied)