Android socket communcation

Question

Im building an android application that connects to a server trough a socket. However I can't notify the mainthread from the worker connection thread, since it would lock the mainthread and android does not allow that. Here is the following code I have:

Part of connection controller:

public void run(){
    while (true){
        while (isRunning){
            if (serverSocket == null){
                try{
                    serverSocket = new Socket("*", *);
                    out = new PrintWriter(serverSocket.getOutputStream(), true);
                    in = new BufferedReader(new InputStreamReader(
                            serverSocket.getInputStream()));
                }
                catch (IOException e){
                    e.printStackTrace();
                }
            }
            if (message != ""){
                try{
                        System.out.println(message);
                        out.println(message);
                        message = "";
                        reply = in.readLine();  
                        isRunning = false;                                          
                }
                catch (IOException e)   {
                    e.printStackTrace();
                }
            }               
        }
    }
}

public void sendMessage(String path,
        HashMap<String, HashMap<String, String>> variables){
    this.reply = "";
    isRunning = true;
    String variablesJSON = JSONValue.toJSONString(variables);
    this.message = path + ":" + variablesJSON;

}

Authentication class:

public boolean register(String email, String password, String displayName)  {
    String path = "User.register";
    HashMap<String, String> variables = new HashMap<String, String>();
    HashMap<String, HashMap<String, String>> user = new HashMap<String, HashMap<String, String>>();
    String hashedPass;
    try{
        hashedPass = sha1(password);
    }
    catch (NoSuchAlgorithmException e){
        e.printStackTrace();
        return false;
    }
    variables.put("displayname", displayName);
    variables.put("password", hashedPass);
    variables.put("email", email);
    user.put("User", variables); 

    connection.sendMessage(path, user, this);

    final ProgressDialog progDailog = ProgressDialog.show(context,
            "Please wait..", "Register", true);
    new Thread(){
        public void run(){
            try{
                while (ConnectionController.getInstance().getIsRunning()){
                    sleep(200);
                }
                progDailog.dismiss();
            }
            catch (Exception e){
                e.printStackTrace();
            }
        }
    }.start();

    Toast.makeText(context.getApplicationContext(),
            ConnectionController.getInstance().getReply(), Toast.LENGTH_LONG)
            .show();
    if (ConnectionController.getInstance().getReply() != "SUCCESS"){
        return false;
    }
    return true;

}

I need to wait for the ProgressDialog to finish, however I can't find a way. I don't think an AsyncTask is the right way todo this since the connection needs to be open all the time. Any hints or ideas?

Answer 1

AsyncTask is the right way to handle this. And all that you need to do to the UI, do it in your onPost method. Infact if you want to call the async in a activity and update the views from the same activity you can

1. Use a Broadcast receiver
2. Make AsyncTask class a inner class to your activity. That way the class methods can modify the views of that activity.

I use trick 2, to get things working. Once I have them working, I take the AsyncTask out, and use BroadcastReceiver's. Just to ease my development and demo time :)