Java安全关闭线程

思路

• 思路1，利用中断标志关闭线程
• 思路2，利用volatile标识变量，线程间可见性共享。

实现1，利用中断关闭线程

public class DemoTest {
    
    public static void main(String[] args) throws InterruptedException {
        Thread t = new Thread(new Worker(), "demo-thread");
        t.start();

        Thread.sleep(500);
        //中断子线程
        System.out.println("=================> main thread execute interrupt");
        t.interrupt();
        // 等待子线程执行完毕
        t.join();

        System.out.println("=================> main thread end");

    }


    static class Worker implements Runnable {
        private long i;

        @Override
        public void run() {
            while(!Thread.currentThread().isInterrupted()) {
                i++;
                System.out.println("=================> i value = " + i);
            }

            System.out.println("=================> finish i value = " + i);
        }
    }
}

实现2，利用volatile标识位关闭线程

public class DemoTest {

    public static void main(String[] args) throws InterruptedException {
        Worker worker = new Worker();
        Thread t = new Thread(worker, "demo-thread");
        t.start();

        Thread.sleep(500);
        //中断子线程
        System.out.println("=================> main thread execute flag = false");
        worker.closeThreadByFlag();
        // 等待子线程执行完毕
        t.join();

        System.out.println("=================> main thread end");
    }


    static class Worker implements Runnable {
        private long i;
        private volatile boolean flag = true;

        @Override
        public void run() {
            while(flag) {
                i++;
                System.out.println("=================> i value = " + i);
            }

            System.out.println("=================> finish i value = " + i);
        }

        public void closeThreadByFlag() {
            flag = false;
        }
    }
}

参考

< Java并发编程的艺术 >