java自动输入验证码 java实现验证码

import java.util.Random;
import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        while (true) {
            String n = getCaptcha();
            System.out.println("验证码为:"+n);
            System.out.println("请输入验证码:");
            Scanner sc = new Scanner(System.in);
            String s = sc.next();
            if (s.equalsIgnoreCase(n)) {
                System.out.println("验证成功！！");
                break;
            }else{
                System.out.println("验证码刷新,请重新输入！");
            }
        }
    }

    public static String getCaptcha() {
        StringBuilder sb = new StringBuilder();
        for (char i = 'a'; i <= 'z'; i++) {
            sb.append(i);
        }
        for (char i = 'A'; i <= 'Z'; i++) {
            sb.append(i);
        }
        for (char i = '0'; i <= '9'; i++) {
            sb.append(i);
        }
        StringBuilder s = new StringBuilder();
        Random r = new Random();
        for (int i = 0; i < 4; i++) {
            int n = r.nextInt(62);
            s.append(sb.charAt(n));
        }
        return s.toString();
    }
}