弱智三個線程輪流打印ABC

import java.util.concurrent.locks.ReentrantLock;

public class PrintABC {
    public static final ReentrantLock lock = new ReentrantLock();
    public static char cnt = 'A';
    public static int times = 0;

    public static void main(String[] args) {
        new Thread(new Ap()).start();
        new Thread(new Bp()).start();
        new Thread(new Cp()).start();
    }


    static class Ap implements Runnable{

        @Override
        public void run() {
            while(true){
                go();
            }

        }
        private void go(){
            try{
                lock.lock();
                if(cnt == 'A' && times < 30){
                    System.out.print(Thread.currentThread().getName()
                            +"---print---A---");
                    cnt = 'B';
                    times++;
                    System.out.println(times);
                }
            }catch(Exception e){
                e.printStackTrace();
            }finally {
                lock.unlock();
            }

        }
    }
    static class Bp implements Runnable{

        @Override
        public void run() {
            while(true){
                go();
            }

        }
        private void go(){
            try{
                lock.lock();
                if(cnt == 'B' && times < 30){
                    System.out.print(Thread.currentThread().getName()
                            +"---print---B---");
                    cnt = 'C';
                    times++;
                    System.out.println(times);
                }
            }catch(Exception e){
                e.printStackTrace();
            }finally {
                lock.unlock();
            }
        }
    }
    static class Cp implements Runnable{

        @Override
        public void run() {
            while(true){
                go();
            }

        }
        private void go(){
            try{
                lock.lock();
                if(cnt == 'C' && times < 30){
                    System.out.print(Thread.currentThread().getName()
                            +"---print---C---");
                    cnt = 'A';
                    times++;
                    System.out.println(times);
                }
            }catch(Exception e){
                e.printStackTrace();
            }finally {
                lock.unlock();
            }
        }
    }
}