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