package senTset;
//紙張類
public class page  {
    private boolean isWrite = false; //設定一個公共變數來控制執行緒執行

     public synchronized void write1() {
            while(isWrite) {   // 公共變數為true時等待
                try {
                    wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

            System.out.print("中"
 
);
            isWrite = true;

            notify();   // 喚醒列印“國”的執行緒
        }

     public synchronized void write2() {
            while (!isWrite) {
                try {
                    wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

            System.out.print("國"
 
);
            isWrite = false;

            notify();   // 喚醒列印“中”的執行緒
        }


        //小紅寫字
        static class xhWrite implements Runnable{
            private page page;

            public xhWrite( page page) {
                this.page = page;
            }

            @Override
            public
 
 void run() {
                for(int i = 0; i < 10; i++) {
                page.write1();
                }
            }

    }
        //小明寫字
        static class xmWrite implements Runnable{
            private page page;

            public xmWrite( page page) {
                this.page = page;
            }
            @Override
            public void run() {
                for(int i = 0; i < 10; i++) {
                    page.write2();
                    }

            }

        }

        public static void main(String[] args) {
            page p = new page();//小明和小紅共用一張紙
            xmWrite xm = new xmWrite(p);
            xhWrite xh = new xhWrite(p);
             Thread t1=new Thread(xm);  
             Thread t2=new Thread(xh);
             t1.start();
             t2.start();
        }

}

就是這樣，如果有什麼不對的地方希望大家指出