android - HttpURLConnection.getInputStream 很慢

Question

与使用相同服务器端服务的 iPhone 应用程序相比，HttpURLConnection.getInputStream 需要花费很多时间。

以下代码用于该服务:

         date= new java.util.Date();             
         Log.d("time","Time Stamp before posting  "+new Timestamp(date.getTime()));

         URL ur= new URL(url);           
         HttpURLConnection conn = (HttpURLConnection) ur.openConnection();
         conn.setRequestProperty("Connection", "close");
         conn.setReadTimeout(10000);
         conn.setConnectTimeout(15000);
         conn.setRequestMethod("POST");
         conn.setDoInput(true);
         conn.setDoOutput(true);             
         OutputStream os = conn.getOutputStream();
         BufferedWriter writer = new BufferedWriter(
                 new OutputStreamWriter(os, "UTF-8"));
         writer.write(getQuery(nameValuePairs));
         writer.close();
         os.close();
         conn.connect();

         StringBuffer response=null;             
         try{           
             Log.d("time","Time Stamp bfr InputStream  "+new Timestamp(date.getTime()));    

             InputStream is = conn.getInputStream();

             date= new java.util.Date();             
             Log.d("time","Time Stamp aftr InputStream  "+new Timestamp(date.getTime()));            

             BufferedReader rd = new BufferedReader(new InputStreamReader(is));
             String line;
             response = new StringBuffer(); 
             while((line = rd.readLine()) != null) {
                 response.append(line);
                 response.append('\r');
             }
             rd.close();
             response.toString();
             result=response.toString();

         } catch (Exception e) {

        }

为了检查服务在哪里花费时间，我将日志条目打印 TimeStamp。

该过程的平均时间如下:

Average time for posting to server takes less than 2 Mil seconds
Average time for creating input stream takes almost 5 seconds

Average time for writing response is less than 2 mil seconds.

知道为什么输入流会花费很多时间导致整个服务非常慢吗？

Answer 1

您没有衡量您认为正在衡量的东西。在您调用 getInputStream() 或 getResponseCode() 之前，不会向服务器写入任何内容。所以你真的在测量:

• 连接时间
• 传输时间
• 服务器处理时间

当您认为自己只是在测量 getInputStream() 时间时。

原因是 HttpURLConnection 通过缓冲所有输出自动设置内容长度 header 。您可以通过使用分块传输模式来避免这种情况。然后至少你会看到时间真正流向了哪里。