Time out method in java

Question

In a java class I have a method that sometimes takes a long time for execution. Maybe it hangs in that method flow. What I want is if the method doesn't complete in specific time, the program should exit from that method and continue with the rest of flow.

Please let me know is there any way to handle this situation.

Answer 1

You must use threads in order to achieve this. Threads are not harmful :) Example below run a piece of code for 10 seconds and then ends it.

public class Test {
    public static void main(String args[])
        throws InterruptedException {

        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println("0");
                method();
            }
        });
        thread.start();
        long endTimeMillis = System.currentTimeMillis() + 10000;
        while (thread.isAlive()) {
            if (System.currentTimeMillis() > endTimeMillis) {
                System.out.println("1");
                break;
            }
            try {
                System.out.println("2");
                Thread.sleep(500);
            }
            catch (InterruptedException t) {}
        }


    }

    static void method() {
        long endTimeMillis = System.currentTimeMillis() + 10000;
        while (true) {
            // method logic
            System.out.println("3");
            if (System.currentTimeMillis() > endTimeMillis) {
                // do some clean-up
                System.out.println("4");
                return;
            }
        }
    }
}

Answer 2

Execute the method in a different thread, you can end a thread at anytime.