在AsyncTask中维护TCP连接
我正在使用AsyncTask建立TCP连接并通过它发送/接收数据。
我目前的代码现在看起来像这样：
public class NetworkTask extends AsyncTask { Socket nsocket; //Network Socket InputStream nis; //Network Input Stream OutputStream nos; //Network Output Stream boolean bSocketStarted = false; byte[] buffer = new byte[4096]; @Override protected void onPreExecute() { Log.i(TAG, "onPreExecute"); } @Override protected Boolean doInBackground(Void... params) { //This runs on a different thread boolean result = false; try { // Connect to address Log.i(TAG, "doInBackground: Creating socket"); SocketAddress sockaddr = new InetSocketAddress("google.de", 80); nsocket = new Socket(); nsocket.connect(sockaddr, 5000); //10 second connection timeout if (nsocket.isConnected()) { bSocketStarted = true; nis = nsocket.getInputStream(); nos = nsocket.getOutputStream(); Log.i("AsyncTask", "doInBackground: Socket created, streams assigned"); Log.i("AsyncTask", "doInBackground: Waiting for inital data..."); int read = nis.read(buffer, 0, 4096); //This is blocking while(bSocketStarted) { if (read > 0){ byte[] tempdata = new byte[read]; System.arraycopy(buffer, 0, tempdata, 0, read); publishProgress(tempdata); Log.i(TAG, "doInBackground: Got some data"); } } } } catch (IOException e) { e.printStackTrace(); Log.i(TAG, "doInBackground: IOException"); result = true; } catch (Exception e) { e.printStackTrace(); Log.i(TAG, "doInBackground: Exception"); result = true; } finally { try { nis.close(); nos.close(); nsocket.close(); } catch (IOException e) { e.printStackTrace(); } catch (Exception e) { e.printStackTrace(); } Log.i(TAG, "doInBackground: Finished"); } return result; } public boolean SendDataToNetwork(final byte[] cmd) { //You run this from the main thread. // Wait until socket is open and ready to use waitForSocketToConnect(); if (nsocket.isConnected()) { Log.i(TAG, "SendDataToNetwork: Writing received message to socket"); new Thread(new Runnable() { public void run() { try { nos.write(cmd); } catch (Exception e) { e.printStackTrace(); Log.i(TAG, "SendDataToNetwork: Message send failed. Caught an exception"); } } } ).start(); return true; } else Log.i(TAG, "SendDataToNetwork: Cannot send message. Socket is closed"); return false; } public boolean waitForSocketToConnect() { // immediately return if socket is already open if (bSocketStarted) return true; // Wait until socket is open and ready to use int count = 0; while (!bSocketStarted && count 0) { Log.i(TAG, "onProgressUpdate: " + values[0].length + " bytes received."); String str = new String(buffer, "UTF8"); Log.i(TAG,str); tv.setText(str); tv.setMovementMethod(new ScrollingMovementMethod()); } } catch (Exception e) { e.printStackTrace(); } finally {} } @Override protected void onCancelled() { Log.i(TAG, "Cancelled."); } @Override protected void onPostExecute(Boolean result) { if (result) { Log.i(TAG, "onPostExecute: Completed with an Error."); } else { Log.i(TAG, "onPostExecute: Completed."); } } } 我可以实例化任务并从我的活动中调用SendDataToNetwork 。 但是，我传递给SendDataToNetwork的所有文本，例如’GET / HTTP / 1.1’都会不断发送到服务器。
如何修改我的代码以维持doInBackground的连接，直到我调用SendDataToNetwork并且在向服务器发送字节后才等到新数据准备好发送之后什么都不做？ 基本上我想运行AsyncTask直到我明确取消（=关闭连接）它。
nsocket.connect(sockaddr, 5000); //10 second connection timeout if (nsocket.isConnected()) {
测试毫无意义。 如果套接字未连接， connect()将抛出exception。
你的阅读循环也存在根本缺陷，因为它不会继续阅读。 有关如何读取流的标准解决方案，例如：
while ((count = in.read(buffer)) > 0) { out.write(buffer, 0, count); }
你的waitForSocketToConnect()方法也没有做任何有用的事情。
你需要重新考虑这一切。