Question

我正在将文件上传到服务器，并且根据文件上的处理，我从服务器得到不同的回复。一切正常，但从服务器获得回复非常慢。我检查了调试器，下面的代码行需要6秒才能运行。

   inStream = new DataInputStream( connection.getInputStream() );

我已经通过网络浏览器测试了相同的文件和代码并且它是完美的，大约需要1或2秒来显示回复。这是我的完整代码，我认为没问题，但也许这里有些东西没有做好。有没有更好的方法呢？或者是一个新的DataInputStream总是会这么慢？

   private String loadImageFromNetwork(String myfile) {
        HttpURLConnection connection = null;
        DataOutputStream outStream = null;
        DataInputStream inStream = null;
        String make = "";
        String model = "";
        String disp = "";
            String lineEnd = "\r\n";
        String twoHyphens = "--";
        String boundary = "*****";

        int bytesRead, bytesAvailable, bufferSize;

        byte[] buffer;

        int maxBufferSize = 1*1024*1024;

        String urlString = "http://xxxxxxxxxxxxxx/upload.php";
        sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + myfile)));

            try {

            FileInputStream fileInputStream = new FileInputStream(new File(myfile));

            // open a URL connection to the Servlet
            URL url = new URL(urlString);

            // Open a HTTP connection to the URL
            connection = (HttpURLConnection) url.openConnection();

            // Allow Inputs
            connection.setDoInput(true);

            // Allow Outputs
            connection.setDoOutput(true);

            // Don't use a cached copy.
            connection.setUseCaches(false);

            // Use a post method.
            connection.setRequestMethod("POST");

            connection.setRequestProperty("Connection", "Keep-Alive");

            connection.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);

            outStream = new DataOutputStream(connection.getOutputStream());

            outStream.writeBytes(twoHyphens + boundary + lineEnd);
            outStream.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\"" + myfile +"\"" + lineEnd);
            outStream.writeBytes(lineEnd);

            // create a buffer of maximum size
            bytesAvailable = fileInputStream.available();
            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];

            // read file and write it into form...

            bytesRead = fileInputStream.read(buffer, 0, bufferSize);

                while (bytesRead > 0) {
                        outStream.write(buffer, 0, bufferSize);
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);
            }

            // send multipart form data necesssary after file data...
                outStream.writeBytes(lineEnd);
                outStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

            // close streams
            fileInputStream.close();
            outStream.flush();
            outStream.close();


          }
          catch (MalformedURLException ex) {
                  ex.printStackTrace();
          }

          catch (IOException ioe) {
                  ioe.printStackTrace();
          }

          //------------------ read the SERVER RESPONSE
          try {

               inStream = new DataInputStream( connection.getInputStream() );

                   String str;

                   while (( str = inStream.readLine()) != null)
                   {
                            disp = disp + str;

                   }

                   inStream.close();


          }
          catch (IOException ioex){
                  ioex.printStackTrace();
          }
          return disp;

    }

Answer 1

您应该移动代码以将服务器的响应读取到新线程。例如：

private class ReadResponse implements Runnable {
  public void run() {
              //------------------ read the SERVER RESPONSE   
      try {   

           inStream = new DataInputStream( connection.getInputStream() );   

               String str;   

               while (( str = inStream.readLine()) != null)   
               {   
                        disp = disp + str;   

               }   

               inStream.close();   


      }   
      catch (IOException ioex){   
              ioex.printStackTrace();   
      }   
      //return disp; 
      //here you need to show your display on UI thread
    }
  }
}

并在上传文件之前启动阅读线程。

打开DataInputStream运行速度很慢

1 个答案: