Android phone communicating with PC: Phone can't find PC

Question

I've got a simple Java server running on my laptop that opens a ServerSocket. A simple client for the android tries to connect to this server (using my laptop's IP address and the port I specified in the ServerSocket), and send it a string. The client hangs on:

client = new Socket(IP_ADDRESS, DEST_PORT);

I'm using a Samsung Galaxy S3 connected to my laptop. Note that I try to establish the connection from the client side in an AsyncTask.

I've been hammering away at this for a while, and have the feeling I'm missing something simple.

So the question is: How do I get my android phone to recognise/see the PC? Thanks in advance!

Here is my Java server code:

// Imports etc

public class Main
{
    private static final int PORT = 4444;

    private static ServerSocket serverSocket;
    private static Socket clientSocket;
    private static InputStreamReader inputStreamReader;
    private static BufferedReader bufferedReader;
    private static String message;

    public static void main(String[] args)
    {
        try
        {
            serverSocket = new ServerSocket(PORT, 0, InetAddress.getLocalHost());

            System.out.println("IP:  " + serverSocket.getInetAddress() + "  Port:  " +  serverSocket.getLocalPort());

        } catch (IOException e)
        {
            System.out.println("Could not listen on port: 4444");
        }

        System.out.println("Server started. Listening to the port 4444");

        while (true)
        {
            try
            {
                clientSocket = serverSocket.accept(); // accept the client connection
                inputStreamReader = new InputStreamReader(clientSocket.getInputStream());
                bufferedReader = new BufferedReader(inputStreamReader); // get the client message
                message = bufferedReader.readLine();

                System.out.println(message);
                inputStreamReader.close();
                clientSocket.close();

            } catch (IOException ex)
            {
                System.out.println("Problem in message reading");
            }
        }
    }
}

Here is my android client code:

// Imports etc

public class SimpleClientActivity extends Activity
{
    private EditText textField;
    private Button button;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        textField = (EditText) findViewById(R.id.editText1); // reference to the text field
        button = (Button) findViewById(R.id.button1); // reference to the send button

        // Button press event listener
        button.setOnClickListener(new View.OnClickListener()
        {

            public void onClick(View v)
            {
                new ConnectToServerTask().execute(textField);
            }
        });
    }
}

Here is my AsyncTask code:

// Imports etc

public class ConnectToServerTask extends AsyncTask<View, Integer, Socket>
{
    private static final String IP_ADDRESS = "192.168.56.1";  // Toshiba laptop
    private static final int DEST_PORT = 4444;

    private EditText mTextField;

    /**
     * Store provided views (used later in onPostExecute(...)).
     * 
     * Create socket to communicate with server (blocking call).
     */
    protected Socket doInBackground(View... params)
    {
        // Store provided views.
        if (params.length != 1)
            throw new IllegalArgumentException();

        mTextField = (EditText) params[0];


        // Create socket.
        Socket client = null;

        try
        {
            client = new Socket(IP_ADDRESS, DEST_PORT); // connect to server
        } catch (UnknownHostException e)
        {
            e.printStackTrace();
        } catch (IOException e)
        {
            e.printStackTrace();
        }

        return client;
    }

    /**
     * Write to server.
     */
    protected void onPostExecute(Socket client)
    {
        try
        {
            PrintWriter printwriter;
            String messsage;

            messsage = mTextField.getText().toString(); // get the text message on the text field
            mTextField.setText(""); // Reset the text field to blank

            printwriter = new PrintWriter(client.getOutputStream(), true);
            printwriter.write(messsage); // write the message to output stream

            printwriter.flush();
            printwriter.close();

            client.close();
        } 
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}

Answer 1

Thanks to @zapl, check the IP address of the PC. Had 192.168.56.1 when the correct address was 192.168.1.56.