如何从服务器向客户端本地主机发布响应

Question

我有一个API实现，它接受加密的数据字符串作为参数，解密数据并将响应发回到加密的数据字符串中提供的url。该程序位于测试服务器上，可供API团队进行测试。

现在，他们正在以加密字符串的形式提供用于回调的localhost Url，尽管服务器能够解密和处理响应，但它在尝试将响应发布到localhost URL时抛出了Connection拒绝错误。

这是试图发布响应并使用Apache HttpClient的代码部分：

public String sendPost(String url, List<NameValuePair> postParams)
        throws IOException, NoSuchAlgorithmException, KeyStoreException, KeyManagementException {
    logger.debug("Post URL: " + url);
    logger.error("Post parameters : " + postParams);

    SSLContext sslContext = new SSLContextBuilder()
            .loadTrustMaterial(null, (certificate, authType) -> true).build();
    CloseableHttpClient httpclient = HttpClients.custom()
            .setSSLContext(sslContext)
            .setSSLHostnameVerifier(new NoopHostnameVerifier())
            .build();

    HttpPost post = new HttpPost(url);
    // add header
    post.setHeader("User-Agent", USER_AGENT);
    post.setEntity(new UrlEncodedFormEntity(postParams));

    try (CloseableHttpResponse response = httpclient.execute(post)) {
        logger.debug("Response : " + response);
        if (response.getFirstHeader("Location") != null) {
            logger.debug("Redirect Location required from response: " + response.getFirstHeader("Location"));
            return response.getFirstHeader("Location").getValue();
        } else {
            logger.debug("Redirect location not found in response. Please wait for some time and try again later.");
            HttpEntity entity = response.getEntity();
            logger.debug("Entity : " + entity);
            if (entity != null) {
                logger.error(EntityUtils.toString(entity));
            }
            return null;
        }
    } finally {
        httpclient.close();
    }
}

我的理解是，服务器正在将回调URL本地主机混淆，并试图在其中发布响应，但该响应被拒绝了。