建立三个线程，A线程打印10次A，B线程打印10次B,C线程打印10次C，要求线程同时运行，交替打印10次ABC。

/*
 * 建立三个线程，A线程打印10次A，B线程打印10次B,C线程打印10次C，要求线程同时运行，交替打印10次ABC。
 */
class Demo implements Runnable {

	int count = 10;
	String name;
	Object pre;
	Object self;

	public Demo(String name, Object pre, Object self) {
		super();
		this.name = name;
		this.pre = pre;
		this.self = self;
	}

	@Override
	public void run() {
		while (count > 0) {
			synchronized (pre) {
				synchronized (self) {
					System.out.print(name);
					count--;
					self.notify();
				}
				try {
					pre.wait();
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}
	}
}

public class Test3 {
	public static void main(String[] args) throws InterruptedException {
		Object a = new Object();
		Object b = new Object();
		Object c = new Object();
		Demo d1 = new Demo("A", c, a);
		Demo d2 = new Demo("B", a, b);
		Demo d3 = new Demo("C", b, c);
		new Thread(d1).start();
		Thread.sleep(100);
		new Thread(d2).start();
		Thread.sleep(100);
		new Thread(d3).start();
		Thread.sleep(100);
	}
}