Apache Mina Chat Client

package com.mukcay.client;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import org.apache.mina.core.RuntimeIoException;
import org.apache.mina.core.future.ConnectFuture;
import org.apache.mina.core.service.IoHandlerAdapter;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.textline.TextLineCodecFactory;
import org.apache.mina.transport.socket.nio.NioSocketConnector;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.net.InetSocketAddress;

public class ClientActivity extends Activity {

    private static final String HOSTNAME = "10.0.2.2";
    private static final int PORT = 1234;
    private static final long CONNECT_TIMEOUT = 30 * 1000L; // 30 seconds
    private IoSession session;
    private NioSocketConnector connector;
    private ConnectFuture future;
    private TextView tw;
    private EditText et;

    private class TCPTask extends AsyncTask<Void, Void, Void> {

        @Override
        protected Void doInBackground(Void... params) {
            connector = new NioSocketConnector();
            connector.setConnectTimeoutMillis(CONNECT_TIMEOUT);
            connector.getFilterChain().addLast("codec", new ProtocolCodecFilter(new TextLineCodecFactory()));
            connector.setHandler(new ClientSessionHandler());

            while(true) {
                try {
                    future = connector.connect(new InetSocketAddress(HOSTNAME, PORT));
                    future.awaitUninterruptibly();
                    session = future.getSession();
                    Log.d("***************************", "Connected.");

                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            appandMessage("Sunucuya bağlanıldı");
                        }
                    });

                    break;
                } catch (RuntimeIoException e) {
                    Log.d("***************************", "Failed to connect.");
                    e.printStackTrace();
                    try {
                        Thread.sleep(5000);
                    } catch (InterruptedException e1) {
                        e1.printStackTrace();
                    }
                }
            }

            // wait until the summation is done
            session.getCloseFuture().awaitUninterruptibly();
            connector.dispose();
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            appandMessage("Bağlantı kapandı!\n");
        }
    }

    public class ClientSessionHandler extends IoHandlerAdapter {
        private final Logger LOGGER = LoggerFactory.getLogger(ClientSessionHandler.class);
        private boolean finished;

        public void sessionOpened(IoSession s) {
            session = s;
        }

        public void messageReceived(IoSession session, Object message) {
            final String mes = (String)message;
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    appandMessage("Mesaj alındı: " + mes + "\n");
                }
            });
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_client);
        tw = (TextView) findViewById(R.id.messageBoard);
        et = (EditText) findViewById(R.id.message);
    }

    public void connectToServerButtonClicked(View v) {
        Log.d("***************************", "connectToServerButtonClicked");
        new TCPTask().execute();
    }

    public void sendMessageButtonClicked(View v) {
        Log.d("***************************", "sendMessageButtonClicked");
        if (session == null) {
            Log.d("***************************", "Session is null");
            return;
        }

        session.write(et.getText());
        et.setText("");
    }

    public void appandMessage(String message) {
        tw = (TextView) findViewById(R.id.messageBoard);
        tw.append(message);
    }
}