//用此方法生成的密钥去唤起小程序会报错 签名错误 我想验证一下签名生成的对错 替换成文档中的密钥 会直接报错 。。 不知道是文档中提供的密钥不对还是此签名生成方式不对
public static String getSign(String signatureStr, String privateKey) throws Exception {
//        String replace = privateKey.replace("\\n", "\n");
        PrivateKey merchantPrivateKey = PemUtil.loadPrivateKeyFromPath(privateKey);
        Signature sign = Signature.getInstance("SHA256withRSA");
        sign.initSign(merchantPrivateKey);
        sign.update(signatureStr.getBytes(StandardCharsets.UTF_8));
        return Base64Utils.encodeToString(sign.sign());
    }

    public static void main(String[] args) {
        String signatureStr = Stream.of("wx2421b1c4370ec43b", "1554208460", "593BEC0C930BF1AFEB40B4A08C8FB242", "prepay_id=" + "wx201410272009395522657a690389285100")
                .collect(Collectors.joining("\n", "", "\n"));
        String sign = null;
        try {
            sign = getSign(signatureStr, "D:\\data\\apiclient_key.pem");
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println(sign);
    }

https://pay.weixin.qq.com/doc/v3/merchant/4012365341 如果密钥文件换成参考文档中的密钥文件会报错