多线程08.优雅结束线程的三种方式

1.使用flag

public class ThreadCloseGraceful {

    private static class Worker extends Thread {
        private volatile boolean start = true;

        @Override
        public void run() {
            while (start) {
                //
            }
        }

        public void shutdown() {
            this.start = false;
        }
    }

    public static void main(String[] args) {
        Worker worker = new Worker();
        worker.start();

        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        worker.shutdown();
    }
}

2.使用线程中断方法结束

public class ThreadCloseGraceful2 {
    private static class Worker extends Thread {

        @Override
        public void run() {
            while (true) {
                if (Thread.interrupted())
                    break;
            }
            //-------------
            //-------------
            //-------------
        }
    }

    public static void main(String[] args) {
        Worker worker = new Worker();
        worker.start();

        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        worker.interrupt();
    }
}

3.使用守护线程结束

public class ThreadService {

    private Thread executeThread;

    private boolean finished = false;

    public void execute(Runnable task) {
        executeThread = new Thread() {
            @Override
            public void run() {
                Thread runner = new Thread(task);
                runner.setDaemon(true);

                runner.start();
                try {
                    runner.join();
                    finished = true;
                } catch (InterruptedException e) {
                    //e.printStackTrace();
                }
            }
        };

        executeThread.start();
    }

    public void shutdown(long mills) {
        long currentTime = System.currentTimeMillis();
        while (!finished) {
            if ((System.currentTimeMillis() - currentTime) >= mills) {
                System.out.println("任务超时，需要结束他!");
                executeThread.interrupt();
                break;
            }

            try {
                executeThread.sleep(1);
            } catch (InterruptedException e) {
                System.out.println("执行线程被打断!");
                break;
            }
        }

        finished = false;
    }
}

测试：

public class ThreadCloseForce {


    public static void main(String[] args) {

        ThreadService service = new ThreadService();
        long start = System.currentTimeMillis();
        service.execute(() -> {
            //load a very heavy resource.
            /*while (true) {

            }*/
            try {
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        });
        service.shutdown(10000);
        long end = System.currentTimeMillis();
        System.out.println(end - start);
    }
}