一个基于java的混淆自增数据库自增id的简单实现

防止数据库条目 ID 直接暴露给前端用户, 传给前端时在dto上转成混淆后的string, 后端接收时由混淆后的string转成long, 其余逻辑不变.

package tech.houxi.learning.service;

public class Main {
    private static final String alphabet = "zFOsDRcPWunIhk01y9Xe6fwSjrgp2HNb5di4QMUaB8CY73EAKZlomqVTGxtJvL";

    public static void main(String[] args) throws Exception {
        long id = 1133;
        System.out.println("id     = " + id);

        String strId = toId(id);
        System.out.println("strId  = " + strId);

        long longId = toLong(strId);
        System.out.println("longId = " + longId);

    }

    // long转str
    public static String toId(Long id) {
        if (id == null) {
            return "";
        }
        if (id < 0) {
            throw new RuntimeException("id必须大于等于0");
        }
        StringBuilder sb = new StringBuilder();
        do {
            int i = (int) (id % alphabet.length());
            sb.append(alphabet.charAt(i));
            id /= alphabet.length();
        } while (id > 0);
        return sb.toString();
    }

    // str转long
    public static Long toLong(String id) {
        if (id == null || id.length() == 0) {
            return null;
        }
        int length = alphabet.length();

        long num = 0;
        for (int i = id.length() - 1; i >= 0; i--) {
            int indexOf = alphabet.indexOf(id.charAt(i));
            if (indexOf == -1) {
                throw new RuntimeException("id错误");
            }
            num = num * length + indexOf;
        }
        return num;
    }
}

输出

#示例一:
id     = 1133
strId  = 9X
longId = 1133

示例二:
id     = 344333
strId  = A4pF
longId = 344333