RSAPublicKeyConfig config = new RSAPublicKeyConfig.Builder()
        .merchantId(ehisPayInfo.getMerchantId())
        .publicKey(ehisPayInfo.getPublicKey())
        .publicKeyId(ehisPayInfo.getPublicKeyId())
        .privateKey(ehisPayInfo.getPrivateKey())
        .merchantSerialNumber(ehisPayInfo.getMchSerialNo())
        .apiV3Key(ehisPayInfo.getApiV3Key())
        .build();
// 构建service
JsapiService service = new JsapiService.Builder().config(config).build();
PrepayResponse response = service.prepay(request);