Android : Android: Communicate with worker thread to send messages

I am trying to send messages from one android device to another via tcp. The sending device sends to a PC used as server which then sends the message to the other device. In order to receive messages I run a thread parallel to the UI-thread which updates the user interface using a handler to show the message. This works fine.

Right now I am using an AsyncTask to send messages, which creates a socket, then sends the message an then closes the socket again. So every time I want to send a message I have to connect and disconnect.

public class SendTask extends AsyncTask<String, Void, Void> {

static final String TAG = "SendTask";

private Socket soc;
private String theIp;
private int thePort;

public SendTask(String pIp, int pPort){
    theIp = pIp;
    thePort = pPort;
}

@Override
protected Void doInBackground(String... arg0) {

    try {
        soc = new Socket(theIp, thePort);
        soc.getOutputStream().write(arg0[0].getBytes());
        soc.close();
    } catch (Exception e) {
        Log.d(TAG, "failed to create socket");      
        e.printStackTrace();
    }

    return null;
}

}

I would rather have a solution where I create a thread which opens the socket and then every time a button is clicked sends a text recevied from an EditText. Is there a solution for this that is similar to the receiving thread? I am struggling with how to tell the created thread when to send a message without accessing the UI from that Thread.

The sending Thread looks as follows:

public class ReceiveClient implements Runnable {

static final String TAG = "ReceiveClient";

public static final int NEW_INPUT = 101;

private Socket soc;
private String theIp;
private int thePort;
Handler handler;

public ReceiveClient(String pIp, int pPort, Handler pHandler){
    this.theIp = pIp;
    this.thePort = pPort;
    handler = pHandler;
}

@Override
public void run() {
    Log.d(TAG, "try to create socket");
    try {
        soc = new Socket(theIp, thePort);
    } catch (Exception e) {
        Log.d(TAG, "failed to create socket");      
        e.printStackTrace();
    }
    Log.d(TAG, "running");
    try {
        while (!Thread.currentThread().isInterrupted()) {
            byte b[] = new byte[16];
            int count = soc.getInputStream().read(b, 0, 16);
            if(count > 0){
                String s = new String(b);
                Log.d(TAG, "received: " + s);
                displayMessage(s);
                }
            }
        Log.d(TAG, "done");
        }catch (Exception e) {
            System.err.println(e);
    }
}

private void displayMessage(String text){
    Message msg = handler.obtainMessage();
    msg.what = NEW_INPUT;
    msg.obj = text;
    handler.sendMessage(msg);
}
}