java多线程的应用-使用两个线程打印12A34B56C78D

基本思路：使用wait/notify机制。

public class ThreadTest{
	public static void main(String[] args){
		Object lock = new Object();
        Thread a = new A(lock);
        Thread b = new B(lock);
        a.start();
        b.start();
	}
}

class A extends Thread{
    
    Object lock;

    public A(Object lock){
        this.lock = lock;
    }

    @Override
    public void run (){
        synchronized(lock){
            for (int i = 1; i <= 8; i++) {
                System.out.println(i);
                if(i%2 == 0){
                    try{
                        lock.notify();
                        lock.wait();
                    }catch (InterruptedException e){
                        e.printStackTrace();
                    }
                }
            }
        }
    }

}

class B extends Thread{

    Object lock;

    public B(Object lock){
        this.lock = lock;
    }

    @Override
    public void run (){
        synchronized(lock){
            for (int i = 1; i <= 4; i++) {
                System.out.println((char)(i+64));
                try{
                    lock.notify();
                    lock.wait();
                }catch(InterruptedException e){
                    e.printStackTrace();
                }
            }
        }
    }

}