Android套接字接收数据

Question

我是 android 开发的新手，所以如果需要任何进一步的信息，请询问...我正在尝试使用套接字将坐标发送到服务器，接收查询结果和 "Toast" 它们。直到现在在我的 activity:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_socket);

    new Thread(new ClientThread()).start();     

}
      ...

 class ClientThread implements Runnable {
             @SuppressWarnings("deprecation")
            @Override
             public void run() {
                 try {
                     InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
                     socket = new Socket(serverAddr, SERVERPORT);

                 } catch (UnknownHostException e1) {
                     e1.printStackTrace();
                 } catch (IOException e1) {
                     e1.printStackTrace();
                 }
             }
         }


      public void onClickk(View view) {
             try {
                // Acquire a reference to the system Location Manager
                LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);............here some more code regarding coordinates. ............

我正在通过套接字写入坐标（以相同的方法）：

                        lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);

                        if (lat!=null){

                            String json = "";

                            // 3. build jsonObject
                            JSONObject jsonObject = new JSONObject();
                            try {
                                jsonObject.accumulate("lat", lat);
                                jsonObject.accumulate("lon", lon);
                            } catch (JSONException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                            }
                            // 4. convert JSONObject to JSON to String
                            json = jsonObject.toString();

                         PrintWriter out = new PrintWriter(new BufferedWriter(
                                 new OutputStreamWriter(socket.getOutputStream())),
                                 true);
                         out.println(json);

如何接收服务器发送的数据？我不知道如何使用 InputSteam。

更新：我的服务器。当从应用程序收到消息时，服务器会尝试在套接字上写入字符串。

       sock.on('data', function(data) {

          console.log('DATA ' + sock.remoteAddress + ': ' + data);

          sock.write(la);
       });

       });

Answer 1

class Client extends Thread {

    public void run()
    {
         try
         {
              Socket socket = new Socket(address, PORT);
              PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
              out.println(json);
              BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
              String response = in.readLine()
              Toast.makeText(MainActivity.this, response, Toast.LENGTH_SHORT).show();
              socket.close();
         }
         catch(Exception e) {}
    }
}

Answer 2

我遇到了类似的问题，最后在这里找到：

https://community.particle.io/t/using-tcp-to-communicate-between-an-android-and-photon-without-cloud-connection/28495/4

MainActivity.java

public class MainActivity extends AppCompatActivity {

    //    private ListView mList;
//    private ArrayList<String> arrayList;
//    private MyCustomAdapter mAdapter;
    private TCPClient mTcpClient;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final Button button = (Button) findViewById(R.id.connectBtn);
        button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                // connect to the server
                TCPClient.buttonPushed = "Kamran Gasimov, hi";
                new connectTask().execute("");
            }
        });



    }

    public class connectTask extends AsyncTask<String,String,TCPClient> {

        @Override
        protected TCPClient doInBackground(String... message) {

            //we create a TCPClient object and
            mTcpClient = new TCPClient(new TCPClient.OnMessageReceived() {
                @Override
                //here the messageReceived method is implemented
                public void messageReceived(String message) {
                    //this method calls the onProgressUpdate
                    publishProgress(message);
                    Log.d("Message", message);
                }
            });
            mTcpClient.run();

            return null;
        }

        @Override
        protected void onProgressUpdate(String... values) {
            super.onProgressUpdate(values);
            Log.d("values", values[0]);
            //in the arrayList we add the messaged received from server
//            arrayList.add(values[0]);
            // notify the adapter that the data set has changed. This means that new message received
            // from server was added to the list
//            mAdapter.notifyDataSetChanged();
        }
    }
}

TCPClient.java

public class TCPClient {

    private String serverMessage;
    public static String buttonPushed;
    public static final String SERVERIP = "192.168.1.100"; //your Photon (formerly computer) IP address

    public static final int SERVERPORT = 7777;
    private OnMessageReceived mMessageListener = null;
    private boolean mRun = false;

    PrintWriter out;
    BufferedWriter out1;
    OutputStreamWriter out2;
    OutputStream out3;
    BufferedReader in;

    /**
     *  Constructor of the class. OnMessagedReceived listens for the messages received from server
     */
    public TCPClient(OnMessageReceived listener) {
        mMessageListener = listener;
    }

    /**
     * Sends the message entered by client to the server
     * @param message text entered by client
     */
    public void sendMessage(String message){
        if (out != null && !out.checkError()) {
            out.println(message);
            Log.d("TCP Client", "Message: " + message);
            out.flush();
        }
    }

    public void stopClient(){
        mRun = false;
    }

    public void run() {

        mRun = true;

        try {
            //here you must put your computer's IP address.
            InetAddress serverAddr = InetAddress.getByName(SERVERIP);

            Log.e("TCP Client", "C: Connecting...");

            //create a socket to make the connection with the server
            Socket socket = new Socket(serverAddr, SERVERPORT);

            try {
                //send the message to the server

                out3 = socket.getOutputStream();
                out2 = new OutputStreamWriter(socket.getOutputStream());
                out1 = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
                out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
                Log.e("TCP Client", "C: out3 = " + out3);
                Log.e("TCP Client", "C: out2 = " + out2);
                Log.e("TCP Client", "C: out1 = " + out1);
                Log.e("TCP Client", "C: out0 = " + out);

                sendMessage(buttonPushed); //this was the key
                Log.e("TCP Client", "C: Sent.");

                Log.e("TCP Client", "C: Done.");

                //receive the message which the server sends back
                in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                Log.e("TCP Client", "C: received = " + in);
                Log.e("TCP Client", "C: run = " + mRun);
                //in this while the client listens for the messages sent by the server
                while (mRun) {
                    Log.e("TCP Client", "C: I got to the while loop!");

                    serverMessage = in.readLine();

                    Log.e("TCP Client", "C: serverMessage = " + serverMessage);
                    new TCPClient(mMessageListener);
                    stopClient();
                    if (serverMessage != null && mMessageListener != null) {
                        //call the method messageReceived from MyActivity class
                        mMessageListener.messageReceived(serverMessage);
                    } else {
                        serverMessage = null;
                    }
                }

                Log.e("TCP Client", "C: run = " + mRun);

                Log.e("RESPONSE FROM SERVER", "S: Received Message: '" + serverMessage + "'");
            } catch (Exception e) {
                Log.e("TCP", "S: Error", e);
            } finally {
                //the socket must be closed. It is not possible to reconnect to this socket
                // after it is closed, which means a new socket instance has to be created.
                socket.close();
                Log.d("TCP Client", "Socket closed.");
                serverMessage = null;
            }

        } catch (Exception e) {
            Log.e("TCP", "C: Error", e);
        }

    }

    //Declare the interface. The method messageReceived(String message) will must be implemented in the MyActivity
    //class at on asynckTask doInBackground
    public interface OnMessageReceived {
        public void messageReceived(String message);
    }
}

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