MD5加密用法

    public Long createCerUser(CerUser user) {
        CerUser ceruser = this.findCerUserByName(user.getYhm());
        if (ceruser != null) user.setId(ceruser.getId());
        user.setMm(createEncryptPSW(user.getMm().trim()));
        this.getHibernateTemplate().saveOrUpdate(user);
        return user.getId();
    }

 加密算法：

private String createEncryptPSW(String psw) {
        MessageDigest messagedigest;
        try {
            messagedigest = MessageDigest.getInstance("MD5");
            messagedigest.update(psw.getBytes("UTF8"));
            byte abyte0[] = messagedigest.digest();
            return (new BASE64Encoder()).encode(abyte0);
        } catch (Exception e) {
            throw new RuntimeException("加密失败：" + e.getMessage());
        }
    }

 登录判断：

    public Long userCer(String userName, String password) {
        TempUser user = this.findTempUserByName(userName);
        if (null == user) return 0L;
        boolean flag = createEncryptPSW(password.trim()).equals(user.getMm());
        if (flag) return user.getId();
        return 0L;
    }

 登录时不是解密，而是与加密输入的密码比较