Android套接字：读取连续数据

Question

I am trying to read data continuously using the following code:

public class MyClientTask extends AsyncTask<Void, Void, Void> {

        String dstAddress;
        int dstPort;
        String response = "";

        MyClientTask(String addr, int port){
            dstAddress = addr;
            dstPort = port;

        }

        @Override
        protected Void doInBackground(Void... arg0) {

            Socket socket = null;

            try {
                socket = new Socket(dstAddress, dstPort);

                ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(1024);
                byte[] buffer = new byte[1024];

                int bytesRead;
                InputStream inputStream = socket.getInputStream();


                while ((bytesRead = inputStream.read(buffer)) != -1){
                    readInpt = inputStream.toString();
                    byteArrayOutputStream.write(buffer, 0, bytesRead);
                    response = byteArrayOutputStream.toString("UTF-8");
                }
                textResponse.setText(readInpt);

            } catch (UnknownHostException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                response = "UnknownHostException: " + e.toString();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                response = "IOException: " + e.toString();
            }finally{
                if(socket != null){
                    try {
                        socket.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            textResponse.setText(response);
            super.onPostExecute(result);
        }

    }

But for some reason, it doesn't show me any output in the textbox. any help would be appreciated.

Answer 1

There are at least two issues in your code.

Frist, I'm not sure the method toString() on the inputStream is going to work, because the documentation says it returns a description of the object (which would be different than the string recieved). You might be confusing this with the contents of buffer which might be what you really want.

readInpt = inputStream.toString();  // Probably wrong

Second. You're updating the User Interface from a background thread, inside doInBackground() , which is always forbidden.

textResponse.setText(readInpt); // Forbidden, move somewhere else, e.g. onPostExecute()

Answer 2

try {
                socket = new Socket(dstAddress, dstPort);

                BufferedReader stdIn = new BufferedReader(new InputStreamReader(socket.getInputStream()));

                while (true) {
                    response = stdIn.readLine();
                    publishProgress(response);
                    Log.i("response", response);

                }

            } catch (UnknownHostException e) {
                // TODO Auto-generated catch block

                e.printStackTrace();
                response = "UnknownHostException: " + e.toString();
            } catch (IOException e) {
                // TODO Auto-generated catch block

                e.printStackTrace();
                response = "IOException: " + e.toString();
            }

            catch (Exception e) {

                e.printStackTrace();
            }

You cannot print it on text field because the socket will listen to the server socket.If server socket does not send any response it will listen to the socket continuously until the response is received.