作业-week11

请用你熟悉的编程语言写一个用户密码验证函数，Boolean checkPW（String 用户 ID，String 密码明文，String 密码密文）返回密码是否正确 boolean 值，密码加密算法使用你认为合适的加密算法

public class UserService {
    public boolean checkPwd(String userId, String original, String encrypted) {
        String md5 = encrypt(original, getSalt(userId));
        return encrypted.equals(md5);
    }
    private String getSalt(String userId) {
        // 根据userid 获取 salt
        return userId;
    }
    private String encrypt(String original, String salt) {
        String passwordMd5 = null;
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            byte[] bytes = md5.digest((original + salt).getBytes(StandardCharsets.UTF_8));
            passwordMd5 = new String(bytes);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return passwordMd5;
    }
}