java多线程交替打印ABC

public class ABC2 {
    private static Lock lock = new ReentrantLock();
    private static int count = 0;
    private static Condition A = lock.newCondition();
    private static Condition B = lock.newCondition();
    private static Condition C = lock.newCondition();

    public static class A implements Runnable {

        @Override
        public void run() {
            lock.lock();
            try {
                for (int i = 0; i < 10; i++) {
                    while (count % 3 != 0) {
                        A.await();
                    }
                    System.out.print("A");
                    count++;
                    B.signal();
                }
            }
            catch(InterruptedException e){
                e.printStackTrace();
            }finally {
                lock.unlock();
            }
        }
    }
    public static class B implements Runnable {

        @Override
        public void run() {
            lock.lock();
            try {
                for (int i = 0; i < 10; i++) {
                    while (count % 3 !=1) {
                        B.await();
                    }
                    System.out.print("B");
                    count++;
                    C.signal();
                }
            }
            catch(InterruptedException e){
                e.printStackTrace();
            }finally {
                lock.unlock();
            }
        }
    }
    public static class C implements Runnable {

        @Override
        public void run() {
            lock.lock();
            try {
                for (int i = 0; i < 10; i++) {
                    while (count % 3 != 2) {
                        C.await();
                    }
                    System.out.println("C");
                    count++;
                    A.signal();
                }
            }
            catch(InterruptedException e){
                e.printStackTrace();
            }finally {
                lock.unlock();
            }
        }
    }

    public static void main(String[] args) {
        Thread a=new Thread(new A());
        a.start();
        Thread b=new Thread(new B());
        b.start();
        Thread c=new Thread(new C());
        c.start();
    }

}