算法：三线程打印

1 condation方式如下，其他方式参考

public class ThreeThreadPrintCondition {


    public static void main(String[] args) {
        ReentrantLock lock = new ReentrantLock();
        Condition conditionA = lock.newCondition();
        Condition conditionB = lock.newCondition();
        Condition conditionC = lock.newCondition();
        Thread thread1 = new Thread(new Runnable1("A", conditionA, conditionB, lock));
        Thread thread2 = new Thread(new Runnable1("B", conditionB, conditionC, lock));
        Thread thread3 = new Thread(new Runnable1("C", conditionC, conditionA, lock));
        thread1.start();
        thread2.start();
        thread3.start();
    }
}

class Runnable1 implements Runnable {
    private String printStr = "";
    private Condition conditionWait;
    private Condition conditionSignal;
    ReentrantLock lock;
    private int count;

    public Runnable1(String printStr, Condition conditionWait, Condition conditionSignal, ReentrantLock lock) {
        this.printStr = printStr;
        this.conditionWait = conditionWait;
        this.conditionSignal = conditionSignal;
        this.lock = lock;
    }

    @Override
    public void run() {
        while (true) {
            lock.lock();
            if (count == 3 * 10 - 1) {
                lock.unlock();
                return;
            }
            System.out.println("输出" + printStr);
            ++count;
            conditionSignal.signalAll();
            try {
                conditionWait.await();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            lock.unlock();
        }
    }

    public boolean needReturn() {

        return count == 3 * 10 - 1;
    }
}