Java多线程轮流打印ABC

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class Main{

    public static void main(String[] args) {
        MultiTest multiTest = new MultiTest();
        new Thread(multiTest::printA).start();
        new Thread(multiTest::printB).start();
        new Thread(multiTest::printC).start();
    }
}

class MultiTest{

    Lock lock = new ReentrantLock();
    Condition condition = lock.newCondition();
    volatile int flag = 1;

    public void printA(){

        for (int i = 0; i< 10; i++) {
            lock.lock();
            try {
                while (flag != 1) {
                    condition.await();
                }
                System.out.println("A");
                flag = 2;
                condition.signalAll();
            } catch (Exception e) {

            } finally {
                lock.unlock();
            }
        }
    }

    public void printB(){
        for (int i = 0; i< 10; i++) {
            lock.lock();
            try {

                while (flag != 2) {
                    condition.await();
                }
                System.out.println("B");
                flag = 3;
                condition.signalAll();

            } catch (Exception e) {

            } finally {
                lock.unlock();
            }
        }
    }

    public void printC(){
        for (int i = 0; i< 10; i++) {
            lock.lock();
            try {
                while (flag != 3) {
                    condition.await();
                }
                System.out.println("C");
                flag = 1;
                condition.signalAll();
            } catch (Exception e) {

            } finally {
                lock.unlock();
            }
        }
    }
}