Java SDK ResponseEntityProxy{[Content-Type: application/json; charset=utf-8,Content-Length: 71,Chunked: false]} 返回体 的String字符串 代码： CertificatesManager certificatesManager = CertificatesManager.getInstance(); // 向证书管理器增加需要自动更新平台证书的商户信息 certificatesManager.putMerchant(merchantId, new WechatPay2Credentials(merchantId, new PrivateKeySigner(merchantSerialNumber, merchantPrivateKey)), apiV3.getBytes(StandardCharsets.UTF_8)); // ... 若有多个商户号，可继续调用putMerchant添加商户信息 // 从证书管理器中获取verifier Verifier verifier = certificatesManager.getVerifier(merchantId); WechatPayHttpClientBuilder builder = WechatPayHttpClientBuilder.create() .withMerchant(merchantId, merchantSerialNumber, merchantPrivateKey) .withValidator(new WechatPay2Validator(verifier)); // ... 接下来，你仍然可以通过builder设置各种参数，来配置你的HttpClient // 通过WechatPayHttpClientBuilder构造的HttpClient，会自动的处理签名和验签，并进行证书自动更新 CloseableHttpClient httpClient = builder.build(); HttpPost httpPost = new HttpPost(url); httpPost.setHeader("Content-Type", "application/json"); HttpEntity entity = new StringEntity(json, StandardCharsets.UTF_8); httpPost.setEntity(entity); try { CloseableHttpResponse response = httpClient.execute(httpPost); return response;