Question

我在处理不返回数据的HTTP URL连接时遇到问题。我正在使用的代码如下......它基本上是一个消息传递客户端，这个方法获取发送给假用户（bot）的任何消息，然后我能够操纵消息，寻找关键词，并从机器人。

public void getMessages(String bot)
{
    xml = "" +
          "xmlMessage=<message type=\"comet.get.message.updates\" "
          + "id=\"" + bot + "\" "
          + "password=\"" + password + "\" />";

    // Replace spaces (partial url encode).
    xml = xml.replace(" ", "%20");

    String serverResponse = "";

    try
    {
        // Build URL
        url = new URL(botUrl);
        request = (HttpURLConnection)url.openConnection();

        // Set the Request Method.
        request.setRequestMethod("POST");
        request.setDoInput(true);
        request.setDoOutput(true);
        request.setUseCaches(false);
        request.setAllowUserInteraction(false);
        request.setRequestProperty("Content-type", "text/xml; charset=" + "UTF-8");

        out = request.getOutputStream();
        writer = new OutputStreamWriter(out, "UTF-8");
        writer.write(xml);
        writer.close();

        String temp = "";

        buff = new BufferedReader ( new InputStreamReader ( request.getInputStream() ) );
        while ( (temp = buff.readLine()) != null )
        {
            serverResponse = serverResponse + temp;
        }

//     XML RESPONSE EXAMPLE
//            xml = "- <message type=\"comet.message.updates\" id=\"chalkboard.status@fdq.att.com\" count=\"2\">z" +
//                        "- <contact id=\"jy5740\" />" +
//                             "<statement text=\"test\" from=\"jy5740\" />" +
//                             "<statement text=\"testing 123\" from=\"jy5740\" />" +
//                          "</contact>" +
//                     "</message>";
    }
    catch (MalformedURLException ex)
    {
        System.out.println("Bad URL: " + ex);
    }
    catch (IOException ex)
    {
        System.out.println("Connection error: " + ex);
    }

    // do stuff with the serverResponse string

如果在方法调用时有未收到的消息，则该方法可以正常工作。问题是自上次检查后没有任何消息。该方法只是停留在while循环中，直到将消息发送到机器人锁定我的应用程序。如何确定服务器是否没有响应？

Answer 1

彗星的点是“长轮询” - 您提出请求，直到有真实的响应或者超时才会完成。换句话说，如果没有消息，我希望readLine的呼叫能够长时间阻止。

如果您需要提出不会花费很长时间才能超时的请求，您需要在某处指定超时（可能在HTTP级别，可能在XML内容中）或使用不同的调用开始 - 可能有一种不同类型的消息用于非挂起请求。

Answer 2

不知道，但这是我的HTTP Post代码：


            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost(UPLOAD_URL);

            MultipartEntity reqEntity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);

            try {
                reqEntity.addPart("param1", new StringBody("yes"));
                reqEntity.addPart("param2", new StringBody("no"));

                httppost.setEntity(reqEntity);

                LOG.debug("executing request " + httppost.getRequestLine());
                HttpResponse response = httpclient.execute(httppost);
                HttpEntity resEntity = response.getEntity();

                String urlImageShack = null;
                if (resEntity != null) {
                    // XML returned by Imageshack
                    String page = EntityUtils.toString(resEntity);
                    LOG.debug("It return: " + page);
                }

HttpURLConnection POST请求返回无值

2 个答案: