public class SyncronizedTest {

    private int value = 1;

    private AtomicInteger value1 = new AtomicInteger(1);

    private Lock lock = new ReentrantLock();

    //sycronized

    public synchronized int getValue() {

        return value ++ ;

    }

    //jdk自带原子操作

    public int getValue1() {

        return value1.getAndIncrement();

    }

    //lock

    public int getValue2() {

        lock.lock();

        int a = value ++ ;

        lock.unlock();

        return a;

    }

    public static void main(String[] args) {

        //此处必须使用同一个实例对象，因为synchronized锁此处针对的是对象，如果实例化2个对象相当于每个对象有一把锁

        SyncronizedTest syncronizedTest = new SyncronizedTest();

        long startTime = System.currentTimeMillis();

        Runnable runnable = () -> {

            for(int i = 0; i < 100; i ++){

                System.out.println(Thread.currentThread().getName() + ",值：" + syncronizedTest.getValue());

                try {

                    Thread.sleep(1000);

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

            }

        };

        Thread thread1 = new Thread(runnable);

        thread1.start();

        Thread thread2 = new Thread(runnable);

        thread2.start();

        Thread thread3 = new Thread(runnable);

        thread3.start();

        Thread thread4 = new Thread(runnable);

        thread4.start();

        Thread thread5 = new Thread(runnable);

        thread5.start();

        while (thread1.isAlive() || thread2.isAlive() || thread3.isAlive() || thread4.isAlive() || thread5.isAlive()) {

            //自旋

        }

        long endTime = System.currentTimeMillis();

        System.out.println("耗时："+ (endTime - startTime));

    }

}