带有Apache库的HttpPost Java

我试图在向服务器发送json文件后从服务器获取确认响应。我看不出下面的问题是什么。我一直在尝试连接到服务器时遇到502错误

谢谢你的帮助

    HttpClient client = new DefaultHttpClient();
    HttpPost post = new HttpPost("https://stage-api.e-signlive.com/aws/rest/services/codejam");
    post.setHeader("Authorization", "Basic Y29kZWphbTpBRkxpdGw0TEEyQWQx");
    post.setHeader("Content-Type", "application/json");

    File file = new File("test.json");

    try{
        post.setEntity(new FileEntity(file, "application/json"));

        HttpResponse response = client.execute(post);
        BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

        String line = "";
        while ((line = rd.readLine()) != null){
            System.out.println(line);
        }
        //System.out.println(response.getStatusLine().getStatusCode());
    }
    catch (IOException e){
        e.printStackTrace();
    }

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502错误代码是服务器错误（“坏网关”）。看见这通常意味着服务器上出现崩溃，但这是由于内部错误，而不是您的请求有问题。您可能希望联系e-Sign Live支持，查看他们的服务器是否已启动。