Java 生成6位随机验证码 (数字和字母)

import java.util.Random;

public class RandomCodeGenerator {
    public static void main(String[] args) {
        String code = generateRandomCode(6);
        System.out.println('Random code: ' + code);
    }

    public static String generateRandomCode(int length) {
        String characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
        Random random = new Random();
        StringBuilder code = new StringBuilder();
        for (int i = 0; i < length; i++) {
            code.append(characters.charAt(random.nextInt(characters.length())));
        }
        return code.toString();
    }
}

运行结果示例：

Random code: Z9JL5C