1. 用synchronized關鍵字實現

/**

• 用程式碼實現兩個執行緒交替列印0-100的奇偶數,用synchronized關鍵字實現
  */

public class WaitNotifyPrintOddEvenSyn {
//2個執行緒
//一個處理偶數，一個處理奇數（使用位運算）
//用synchronized來通訊
private static int count;
private static final Object lock =new Object();
public static void main(String[] args) {
new Thread(new Runnable() {
@Override
public void run() {
while (count<100){
synchronized (lock){
//使用位運算 0代表偶數，1代表奇數
if((count & 1) == 0){
System.out.println(Thread.currentThread().getName()+":"+count++);
}
}
}
}
},"偶數").start();

    new Thread(new Runnable() {
        @Override
        public void run() {
            while (count<100){
                synchronized (lock){
                    //使用位運算  0代表偶數，1代表奇數
                    if((count & 1) == 1){
                        System.out.println(Thread.currentThread().getName()+":"+count++);
                    }
                }
            }
        }
    },"奇數").start();
}
 

}

2. 使用wait/notify

/**

• 兩個執行緒交替列印0~100奇偶數，用wait/notify
  */
  public class WaitNotifyPrintOddEveWait {
  //1.拿到鎖就列印
  //2.列印完，喚醒其他執行緒，就休眠
  private static int count =0;
  private static final Object lock = new Object();

  public static void main(String[] args) throws InterruptedException {
  Thread thread = new Thread(new TurningRunner(),"偶數");
  Thread thread1 = new Thread(new TurningRunner(),"奇數");
  thread.start();
  Thread.sleep(10);//稍作休眠，防止執行緒啟動的順序不一致
  thread1.start();
  }

  static class TurningRunner implements Runnable{
  @Override
  public void run() {
  while (count<=100){
  synchronized (lock){
  //拿到鎖就列印
  System.out.println(Thread.currentThread().getName()+":"+count++);
  //只有兩個執行緒，所以喚醒使用notify和notifAll 一樣，喚醒那個睡眠的鎖
  lock.notify();
  if(count<=100){
  try {
  //如果任務還沒結束，就讓出當前的鎖，讓自己去休眠
  lock.wait();
  } catch (InterruptedException e) {
  e.printStackTrace();
  }
  }
  }
  }
  }
  }

}