example7_7.java

书中的例题

/* 模拟银行帐户类 */
class Mbank 
{
  private static int sum=2000;
  public synchronized static void take(int k) 
	{
	  int temp=sum;
	  temp-=k;
	  try{Thread.sleep((int)(1000*Math.random()));}
	  catch(InterruptedException e){   }
	  sum=temp;
	  System.out.println("sum="+sum);
	}
}

/* 模拟用户取款的线程类 */
class Customer extends Thread
{
	public void run()
	{
		for (int i=1;i<=4 ;i++ )
		{
			Mbank.take(100);
		} 
	}
}

/* 调用线程的主类 */
public class Example7_7
{
  public static void main(String[] args) 
	{
		Customer c1 = new Customer();
        Customer c2 = new Customer();
		c1.start();
		c2.start();
	}
}