Question

Is it possible to connect two phones using socket programming?
I tried following code but it didn’t work

 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    serverStatus = (TextView) findViewById(R.id.server_status);

    SERVERIP = getLocalIpAddress();//Public function to get ip address to it is //working fine 

    Thread fst = new Thread(new ServerThread());
    fst.start();
}

public class ServerThread implements Runnable {

    public void run() {
        try {
            if (SERVERIP != null) {
                handler.post(new Runnable() {
                    public void run() {
                        serverStatus.setText("Listening on IP: " + SERVERIP);
                    }
                });
                serverSocket = new ServerSocket(8087);
                   } else {
                handler.post(new Runnable() {
                    public void run() {
                        serverStatus.setText("Couldn't detect internet connection.");
                    }
                });
            }
        } catch (Exception e) {
            handler.post(new Runnable() {
                public void run() {
                    serverStatus.setText("Error");
                }
            });
            e.printStackTrace();
        }
    }
}

Answer 1

Yes, it is possible but I think the first thing you should do is read up on Java Socket programming as there are a few problems with your code that make me think you haven’t quite got a grasp of it yet. The main problems are:

1. Your ServerSocket never accepts a connection and is therefore never actually ‘listening’.
2. Even if it was listening, if this code is running on both phones they would both only be listening and not actively seeking a connection with each-other.

You will need to implement a client on one phone and a server on the other like @Deepak has shown.

Also, you may want to check out AsyncTask in this article for updating views from a non-UI thread (instead of a handler).

Finally, make sure your app includes the android.permission.INTERNET permission in AndroidManifest.xml.