Android send data from main UI thread to another thread

Question

I need to send some data from the main thread to another thread. I\'ve already read a lot of materials on threads, asynctasks and handlers but maybe they created some confusion

Answer 1

You could solve it using standard Java ways for consumer / producer problems, i.e. a BlockingQueue consumed by a thread and any amount of threads that produce data.

public class SendingWorker {
    private final BlockingQueue sendQueue = new LinkedBlockingQueue();
    private volatile Socket socket;

    public void start() {
        thread.start();
    }

    public void stop() {
        // interrupt so waiting in queue is interrupted
        thread.interrupt();
        // also close socket if created since that can block indefinitely
        Socket socket = this.socket;
        if (socket != null) {
            try {
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    // adding to queues is thread safe
    public void send(Draw draw) {
        sendQueue.add(draw);
    }

    private final Runnable task = new Runnable() {
        @Override
        public void run() {
            try {
                socket = new Socket(InetAddress.getLocalHost(), 8000);
                OutputStream out = socket.getOutputStream();
                while (true) {
                    Draw draw = sendQueue.take();
                    out.write(draw);
                    out.flush();
                }
            } catch (Exception e) {
                // handle 
            } finally {
                // cleanup
            }
        }
    };
    private final Thread thread = new Thread(task);
}