java实现线程交替打印1-52和A-Z

题目：

 1.开启两个线程，一个线程打印A～Z，两一个线程打印1～52的数据。

 2.实现交替打印，输出结果为12A34B...........5152Z.

 3.请用多线程方式实现。

实现思路：通过锁(synchronized) 与wait()，notifyAll()的 或者lock、await()、signal()来实现，废话不多说，直接上代码：

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

/**
 * @author admin
 * @create 2019-12-27-15:08
 */
public class Print {
    public boolean letterFlag = true;//线程结束标记;
    public boolean numFlag = true;
    //数字的初始值
    int num = 1;
    //这里A~Z的字母对应的阿拉伯数字为65～90，
    int letter = 65;
    //线程等待标记
    boolean flag = true;
    Lock lock = new ReentrantLock();
    Condition condLetter = lock.newCondition();
    Condition condNum = lock.newCondition();

    public void printLetter() {
        if(letter>90){
            letterFlag =false;
            return;
        }
        lock.lock();
        try {

            if (flag){
                condLetter.await();
            }
            System.out.print((char)letter);
            letter++;
            flag=true;
            condNum.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }


    public void printNum() {
        if(num>=52){
            numFlag =false;
            return;
        }
        lock.lock();
        try {

            if (!flag){
                condNum.await();
            }
            System.out.print(num);
            num++;
            System.out.print(num);
            num++;
            flag=false;
            condLetter.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
    public static void main(String[] args) {
        Print print =new Print();
        new Thread(new Runnable() {
            @Override
            public void run() {
             while (print.numFlag){
                 print.printNum();
             }
            }
        }).start();


        new Thread(new Runnable() {
            @Override
            public void run() {
             while (print.letterFlag){
                 print.printLetter();
             }
            }
        }).start();
    }

}

运行结果为：

12A34B56C78D910E1112F1314G1516H1718I1920J2122K2324L2526M2728N2930O3132P3334Q3536R3738S3940T4142U4344V4546W4748X4950Y5152Z