How to end a thread in executor service if thread takes too long?

Sample executor service

 static class MyRunnable implements Runnable {

    private String serverName;

    public MyRunnable(String serverName) {
        super();
        this.serverName = serverName;
    }

    @Override
    public void run() {
        ...
        conn = new ch.ethz.ssh2.Connection(serverName);
        conn.connect();

        boolean isAuthenticated = conn.authenticateWithPassword(user, pass);
        logger.info("Connecting to " + server);

        if (isAuthenticated == false) {
            logger.info(server + " Please check credentials");
        }

        sess = conn.openSession();
        ...

    }

}

public static void main(String[] args) {
    List<String> serverList = ...;
    ExecutorService executor = Executors.newFixedThreadPool(20);

    for (String serverName : serverList) {
        MyRunnable r = new MyRunnable(serverName);
        executor.execute(r);
    }

    executor.shutdown();
    executor.awaitTermination(1, TimeUnit.HOURS);
}

Right here is a sample code of my executor service. But with this logic when I meet a server that fails to connect or takes too long to connect it creates a a hang time within my application. I want to end/kill the thread if it takes longer than x amount of time to connect. How can I terminate the thread task if it does not connect to server within 2 seconds.

Attempt

       ThreadPoolExecutor executor = new ThreadPoolExecutor(
                10, 25, 500, TimeUnit.MILLISECONDS,
                new LinkedBlockingQueue<>(1));

I added the following code but apparently it does not end the thread if it takes longer than 2000 milliseconds.

Attempt 2

Future<?> future = executor.submit( new task));
            try {
                future.get(2000, TimeUnit.MILLISECONDS); // This waits timeout seconds; returns null
            }

            catch(TimeoutException e) {
                future.cancel(true);
               // System.out.println(server + "name");
            }

Solution

How can I terminate the thread task if it does not connect to server within 2 seconds.

This is difficult thing to do typically because even if you interrupt the thread (like the other answers mention) there's no guarantee that the thread will stop. Interrupt just sets a flag on the thread and it's up to the code to detect the status and stop. This means that a ton of threads may be in the background waiting for the connects.

In your case however you are using the ch.ethz.ssh2.Connection.connect() method. Turns out there is a connect method that takes a timeout. I think you want the following:

// try to connect for 2 seconds
conn.connect(null, 2000, 0);

To quote from the connect method javadocs:

In case of a timeout (either connectTimeout or kexTimeout) a SocketTimeoutException is thrown.