Question

I have written code for server and client sockets.
I have used threads using handler.But it often gives exception that Only the original thread that created a view hierarchy can touch its views
How to manage to manage this?

Here is the code for Server Socket

 public class ServerThread implements Runnable {

    public void run() { 
        try {
            Looper.prepare();
            if (SERVERIP != null) {
                handler.post(new Runnable() {
                    public void run() {
                        serverStatus.setText("Listening on IP: " + SERVERIP);
                    }
                });
                serverSocket = new ServerSocket(SERVERPORT);
                Toast.makeText(getApplicationContext(), serverSocket.getLocalSocketAddress().toString()
                , Toast.LENGTH_LONG).show();
                serverStatus.append("\n"+serverSocket.getLocalSocketAddress().toString());
                while (true) {
                    // listen for incoming clients
                    Socket client = serverSocket.accept();

                            serverStatus.setText("Connected.");


                    try {
                        BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
                        String line = null;
                        while ((line = in.readLine()) != null) {
                            Log.d("ServerActivity", line);
                            handler.post(new Runnable() {
                                public void run() {

                                }
                            }); 
                        }
                        break;
                    } catch (Exception e) {
                        handler.post(new Runnable() {
                            public void run() {
                                serverStatus.setText("Oops. Connection interrupted. Please reconnect your phones.");
                            }
                        });
                        e.printStackTrace();
                    }
                }
            } else {
                handler.post(new Runnable() {
                    public void run() {
                        serverStatus.setText("Couldn't detect internet connection.");
                    }
                });
            }
        } catch (final Exception e) {
            handler.post(new Runnable() {
                public void run() {
                    serverStatus.setText("Error"+e.getMessage());

                }
            });
            e.printStackTrace();
        }
    }
}

Code for client Socket

  public class ClientThread implements Runnable {

    public void run() {
        try {
            InetAddress serverAddr = InetAddress.getByName(serverIpAddress);
            Log.d("ClientActivity", "C: Connecting...");
            Socket socket = new Socket(serverAddr, 8080);
            connected = true;

                try {
                    console.append("\nC: Sending command.");
                    PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket
                                .getOutputStream())), true);
                        // where you issue the commands
                        out.println("Hey Server!");
                        console.append("C: Sent.");
                } catch (Exception e) {
                    console.append("S: Error= "+ e.getMessage());
                }

            socket.close();
            console.append("\nC: Closed.");
        } catch (Exception e) {
            Log.e("Client :", e.getMessage());

            //console.append("\nC: Error= ");
            connected = false;
        }
    }
}

Here console is the text view where i am trying to put some messages.
I can see messages in the log but not on the text view

Answer 1

Only the original thread that created a view hierarchy can touch its views How to manage to manage this?

Use runOnUiThread(). Or, use a Handler. Or, use post().