Stop thread after button click

Question

I have created a thread on and called that on button click:

btnUpload.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
         new Thread(new ClientThread()).start();
    }
});

This is my main thread:

class ClientThread implements Runnable {

        @Override
        public void run() {

            try {
                InetAddress serverAddr = InetAddress.getByName(SERVER_IP);

                socket = new Socket(serverAddr, SERVERPORT);

            } catch (UnknownHostException e1) {
                e1.printStackTrace();

            } catch (IOException e1) {
                e1.printStackTrace();

            }

        }

    }

I need to stop the thread after actions of button click. How will I do it? I have tried Boolean, interrupt methods but not working. How can I stop it? Please help me.

You may refer to http://stackoverflow.com/questions/22166832/how-to-stop-a-java-code-from-running-via-a-command-button/22167034#22167034 Hope this helps. — Tanmay Patil, Mar 19 '14 at 09:34
probably by stopping the thread, you mean closing the socket created in `run()` ? — mangusta, Mar 19 '14 at 09:46
@androidsuckzzz make that socket an instance variable of `ClientThread` and put some mutator method to close it when necessary, or close it by calling directly from `ClientThread` object — mangusta, Mar 19 '14 at 09:51
Stopping threads like that is dangerous. Please read http://docs.oracle.com/javase/1.5.0/docs/guide/misc/threadPrimitiveDeprecation.html — desidigitalnomad, Mar 19 '14 at 10:36

score 0 · Answer 1 · answered Mar 19 '14 at 09:58

Try this test code:

public class Test3 {
    public static void main(String[] args) throws InterruptedException, IOException {
        Thread serverThread = new Thread(new ServerThread());
        serverThread.start();

        ClientThread client = new ClientThread();
        Thread clientThread = new Thread(client);
        clientThread.start();
        Thread.sleep(5000);
        client.closeSocket();
    }
}

class ServerThread implements Runnable {
    @Override
    public void run() {
        try {
            ServerSocket serverSocket = new ServerSocket(7777);
            serverSocket.accept();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

class ClientThread implements Runnable {
    Socket socket;

    public void closeSocket() throws IOException {
        socket.close();
    }

    @Override
    public void run() {
        try {
            InetAddress serverAddr = InetAddress.getByName("127.0.0.1");
            socket = new Socket(serverAddr, 7777);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

This succesfully closes socket and exits thread.

score 0 · Answer 2 · answered Mar 19 '14 at 14:24

I guess what you are trying to do is to start the socket and then wait for some event (eg. a button click) and then stop it. You can use guarded blocks to wait on a flag.

Your class will look like this

class ClientThread implements Runnable {

    private static final int SERVERPORT = 0;
    private static final String SERVER_IP = null;
    Socket socket;
    boolean stopFlag;

    public ClientThread(){
        stopFlag = false;
    }

    public void setStopFlag(){
        stopFlag = true;
    }

    @Override
    public void run() {

        try {
            InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
            socket = new Socket(serverAddr, SERVERPORT);
            synchronized(this){
                while(!stopFlag){
                    try {
                        wait();
                    } catch (InterruptedException e) {}
                }
            }
            socket.close();

        } catch (UnknownHostException e1) {
            e1.printStackTrace();

        } catch (IOException e1) {
            e1.printStackTrace();
        }
    }

}

When you start the clientThread, hold the instance so that you can signal it later.

ClientThread ct = new ClientThread();
new Thread(ct).start();

When you want to stop the socket(eg. from a button click), do this

synchronized(ct){
   ct.setStopFlag();
   ct.notifyAll();
}

More information about guarded blocks can be found here - http://docs.oracle.com/javase/tutorial/essential/concurrency/guardmeth.html

I recommend you read the whole java concurrency tutorial -http://docs.oracle.com/javase/tutorial/essential/concurrency/index.html

Concurrency is a very interesting and challenging topic. The syntax to start a thread may be simple enough but don't let that mislead you.

score -1 · Answer 3 · answered Mar 19 '14 at 09:25

-1

Call wait() method on the thread whenever button is clicked or event happens (whenever you desire) and again call notify() method to resume the thread

answered Mar 19 '14 at 09:25

Stunner

961
2
19
39

Can you explain? These methods are using in the case of multiple threads! – androidGenX Mar 19 '14 at 09:26
I suggest you to read API of [Thread](http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html) class methods first before you use them. – Stunner Mar 19 '14 at 09:29
multiple threads?? Yes. and for your information main method is also a thread. so when you create another thread, don't you have multiple threads??? Understand threads concept first and then use them. – Stunner Mar 19 '14 at 09:33

score -1 · Answer 4 · answered Mar 19 '14 at 09:45

-1

private Thread thread = new Thread(new ClientThread());
private boolean isStarted = false;
btnUpload.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            if (!isStarted)
                thread.start();
            else
                thread.stop();
    }
});

Try this.

answered Mar 19 '14 at 09:45

Tony Lin

765
3
15
35

This wont wok, this is depreciated. – androidGenX Mar 19 '14 at 09:46

Stop thread after button click

4 Answers4