MainActivity.java

public class ConnectTask extends AsyncTask<String, String, TcpClient> {

        @Override
        protected TcpClient doInBackground(String... message) {
            //we create a TcpClient object
            stat = true;
            mTcpClient = new TcpClient(new TcpClient.OnMessageReceived() {
                @Override
                public void messageReceived(final String message) {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            EditText text = findViewById(R.id.editIO);
                            text.append(message + "\n");
                        }
                    });

                }
            }, ip1, port1);
            mTcpClient.run();

            return null;
        }
    }