public class ThreadDemo
{
// 測試
public static void main(String[] args) throws Exception
{
Object obj = new Object();
// 啟動兩個執行緒
Thread1 t1 = new Thread1(obj);

Thread2 t2 = new Thread2(obj);

t1.start();
t2.start();
}

}

// 一個執行緒列印1-52
class Thread1 extends Thread
{
private Object obj;

public Thread1(Object obj)
{
this.obj = obj;
}

public void run()
{
synchronized (obj)
{
// 列印1-52
for (int i = 1; i < 53; i++)
{
System.out.print(i + " ");
if (i % 2 == 0)
{
// 不能忘了 喚醒其它執行緒
obj.notifyAll();
try
{
obj.wait();
}
catch (InterruptedException e)
{
e.printStackTrace();
}
}
}
}

}

}

// 另一個執行緒列印字母A-Z
class Thread2 extends Thread
{
private Object obj;

public Thread2(Object obj)
{
this.obj = obj;
}

public void run()
{
synchronized (obj)
{
// 列印A-Z
for (int i = 0; i < 26; i++)
{
System.out.print((char)('A' + i) + " ");
// 不能忘了 喚醒其它執行緒
obj.notifyAll();
try
{
// 最後一個就不要等了
if (i != 25)
{
obj.wait();
}
}
catch (InterruptedException e)
{
e.printStackTrace();
}

}

}
}

}