package com.study.demo12; public class TestVerifyCodeLogic { public static void main(String[] args) { String timestamp = String.valueOf(System.currentTimeMillis()); String last4Digits = timestamp.substring(timestamp.length() - 4); String code = "CODE" + last4Digits; System.out.println("完整时间戳: " + timestamp); System.out.println("时间戳后4位: " + last4Digits); System.out.println("生成的验证码: " + code); System.out.println("验证码格式正确: " + (code.startsWith("CODE") && code.length() == 8)); } }